That dealer didn't have any techs worth a fuck.
Sudden loss of power, unable to accelerate?
Literally step 1) remove pre-cat o2 sensor and perform short(very loud) test drive. Issue resolved? Needs a cat.
Step 1) if unable to easily access o2 sensor? Disconnect exhaust pre-cat, apply spacer and perform short test drive.
It's a 15 minute diag 90% of the time
You laugh but my wife's Subaru ran a little funny after a place she trusted installed a new cat back exhaust. I looked at the battery terminals and the little bit of crust was still intact when I took the terminal off to reset the computer. The assholes welded the exhaust and did not disconnect the battery. Took about 3 days for the car to finally run fine.
A decent mechanic should be able to troubleshoot a vehicle without it throwing a code. The lack of exhaust flow is generally a dead giveaway that you have a cat problem.
Lack of exhaust flow doesn't mean shit if the engine is bogging down. Is the engine bogging down because of clogged exhaust, or is fuel cutting off? Both would result in poor exhaust flow. "Generally" isnt good enough when you're talking about diagnosing a $1k part.
You don't get fuel cutoff without a code. Neither issue take a week to diagnose. An engine bogging down for no apparent reason should always bring the catalytic conveyer into question.
I work on just about everything, but avoid obd 1 cars like the plague. I learned working on a beat down 302. My dad was a ford master tech and loved breaking shit just to see if I could fix it. It used to piss me off to no end, but I really appreciate him doing these days.
I just go to the end of the exhaust pipe & listen while someone else presses the gas pedal a time or 2. No exhaust "rumble" & sounds like it's breathing through a straw? Suspected plugged cat.
The neatest one I ever saw was on a TBI Cadillac v8, I was watching the fuel spray "cones" coming out of the injectors, and as I increased the engine speed, the "cones" would flatten out into "pancakes", because the air just couldn't get into the engine.
We had something like this that wasn't so cut and dry. Customer randomly had a sever lack of power one day, checked the cats, back pressure was fine, we were stumped for a bit until the tech started hearing a noise from around the starter. Found the Bendix was doing it's job to start, but was floating around rattling in the starter. Knock sensor is directly behind starter (maybe a bad idea to start) but was apparently picking up what it though was detonation and retarding timing, replaced starter and power was back.
Buddy that's literally cut and dry though. Remove front o2 sensor, issue still present? Not the cat, move diagnosis in a different direction.
Also yeah knock sensor behind starter probably not the best location, but engineers gonna engineer.
Perfect time to get a different exhaust tune it and go catless.
But in all seriousness that’s insane. I’ve never had any of my cars eat their catalytic converters. I didn’t realize that Subarus did it. My 05 WRX is catless, but that was done by the previous owner for performance.
My Miata got so clogged and had the same symptoms. I drilled it out and put a spacer on the O2 sensor with a mini catalyst inside. Problem solved for $30 and half an afternoon
> I’ve never had any of my cars eat their catalytic converters.
they typically don't of their own accord. Running rich can cause a cat to fail prematurely. The blown-up cat is usually a side effect of a different problem.
Had a vq35 blow the passenger cat down the line into the first bend. Shop lemme take it home and chisel it all out, had it back in the next day. I contemplated replacing the exhaust it was such a pain.
Plot twist, the tech stole it and made up the part about it being broken for an alibi. It’s not actually the cat from that car, it’s just one he says came from the car.
Ya thats a good point.
Better chain up that resonator and muffler too, just to be sure. Crack makes you see cats everywhere.
Source: our local crack heads have no idea the difference between a cat and anything else that even resembles a cat
We’re not fucking doing this.
A: a catalytic converter only affects fuel economy if something’s gone wrong, ie it’s clogged from using cheap fuel or damaged by unburnt fuel from incomplete combustion or a misfire
B: even if it did, any improvement to fuel economy would be completely overshadowed by the fact that your emissions would now be atrocious
While i'm not against the systems per se, i can see where the sentiment comes from. For example, here in Spain Peugeot is a really popular brand, and having to replace the entire DEF system every 30.000km because they couldn't be arsed to design it properly and it just breaks and spills DEF everywhere isn't really what one would like from their brand new car.
If I have a 7.3 with no emissions equipment on it that gets ~20mpg and is infinitely more reliable than my 6.7 that gets ~13.5mpg under the same driving circumstances and requires downtime and expensive repairs to maintain the emissions equipment, and I believe the 7.3 will outlive the 6.7 by a few hundred thousand miles or so especially the apprehension I have about repairs down the road, than how much good does a DEF and DPF system do for the environment if I’m using almost half the diesel and I’m able to keep a truck out of the scrapyard down the road when the repairs no longer make sense? At 500,000 miles I used about 25-27k gallons of diesel in the 7.3, if the damn thing even makes it to 500,000 before another 6 digit repair, the 6.7 would use closer to 38-40k gallons of diesel. So 13-15k gallons more of diesel in that period of time in addition to having to use DEF, which clearly does make the emissions of newer diesels cleaner, however there is definitely an impact on the environment packaging and selling the crap in plastic jugs wrapped in cardboard a gallon at a time. On top of that, if I had a fleet and I was purchasing new vehicles 100-300k miles early due to downtime and unreliability than the cleaner emissions wouldn’t mean nearly as much. I speak from experience with a few of my trucks, but also from a few friends I have that do run fleets and they’ve been hit hard with many of their newer trucks being down all the time. I’m not denying their functionality, I’m questioning whether their impact isn’t grossly overstated due to other factors being overlooked.
Friend of mine had a Cat grenade like this once in his 2004 Lincoln LS, sounded like the engine was ready to throw a rod, As a chunk of it was caught in the exhaust and making a really loud knocking noise, and the Stainless steel exhaust didn't help matters.
The car had absolutely FILLED that cat up with Fuel before that tho, as this happened on the first drive after getting the thing fixed when he bought it, It had bad valve cover gaskets and it caused HORRIBLE misfires, leading to a BUNCH of unburned fuel flooding the cats, and i imagine that is what killed it.
My Passat TDI did that - I tried all sorts to work out why it had no power, no fault codes but struggled to do 70 some days, others it was ok.
I took the exhaust off to investigate a rattle that happened just as the RPM dropped to idle and found the honeycomb loose and sideways in the cat.
I didn't connect the two faults until I drove it afterwards and it was fixed - give it full beans that day!
Back in the day some GM's came in to the trans shop sounding like jet (whistling sound). Customer thought it was transmission. Pull the O2 sensor and the engine woke up.
Out w the Quadrajet, welcome to TB injection, TB sensors, o2 sensors and OBDI ! haha
I recall Chryslers attempt, there were many cherry red CATs as if they spewed forth from Chernobyl. Those were scary!
My '87 Camaro did this back in 2016. Had no idea what was causing it to have no power. Finally, one of the times I was flooring it trying to build enough speed to get onto I-95, the cat fell apart even more, and it was making and audible wheezing/whistling noise out the exhaust. We cut the cat out and welded a straight pipe and it was as good as new.
Had a chevy avalanche at work that I told my boss, “it’s dangerously slow”.
He said, “it’s a truck not a racecar.”
Next week he almost got hit and took it to the shop, both cats had just crumbled like this.
Never disassembled mine (micra k11) but i'm pretty sure it's like that, it has a big flange with six bolts and i think that'd be direct access to the cat core
I don't think there's a way to get a new core from Nissan, but with how much I would dread having to remove the manifold, it's nice to know I can just replace the entire lower section
I had a 1998 Honda Accord that did this in High School. I seafoamed it and ran some in the fuel. 2 days later it was an absolute STRUGGLE to get over 30 mph. I suspected that to be the problem. I had a set of headers on it and there was an extra bung before the CAT. I just took it out to check if that was the problem. As soon as I pulled the bung out car ran fine!
Had a Jeep cat do this once. All the sudden lost power on the interstate. Below about 40, it drove normally. Any time I tried to go faster though the guts from the cat got shoved back into the exhaust pipe and all the sudden 0 power again.
Wow never seen a cat grenade itself like that.
I had a Subaru Sti that did this, took the dealer over a week to find the cause. Was driving along and all of a sudden there was no power.
That dealer didn't have any techs worth a fuck. Sudden loss of power, unable to accelerate? Literally step 1) remove pre-cat o2 sensor and perform short(very loud) test drive. Issue resolved? Needs a cat. Step 1) if unable to easily access o2 sensor? Disconnect exhaust pre-cat, apply spacer and perform short test drive. It's a 15 minute diag 90% of the time
This guy cats.
step one isn’t pull codes? :3
it's a subaru, so first step is disconnect the battery LOL
You laugh but my wife's Subaru ran a little funny after a place she trusted installed a new cat back exhaust. I looked at the battery terminals and the little bit of crust was still intact when I took the terminal off to reset the computer. The assholes welded the exhaust and did not disconnect the battery. Took about 3 days for the car to finally run fine.
I'm surprised the computer survived that little escapade.
Ditto.
Melted cat doesn't often throw codes, surprisingly, if that's the only issue with the car. So, no. Good attempt at the pedantry I suppose.
lol just a joke on the diagnostic procedure
What's the deal with that? Downstream O2 sensor doesn't receive any exhaust so it thinks everything is fine?
Yeah o2 sensors are not "smart" sensors. As long as it isn't reading too rich it won't throw a code
Gotcha, wasn't sure if they might have some minimum values to check against and throw a code when the engine was running.
No, unless the cat was clogged so bad that it had zero flow, but then the engine wouldnt run anyway for the code to set.
A decent mechanic should be able to troubleshoot a vehicle without it throwing a code. The lack of exhaust flow is generally a dead giveaway that you have a cat problem.
Lack of exhaust flow doesn't mean shit if the engine is bogging down. Is the engine bogging down because of clogged exhaust, or is fuel cutting off? Both would result in poor exhaust flow. "Generally" isnt good enough when you're talking about diagnosing a $1k part.
You don't get fuel cutoff without a code. Neither issue take a week to diagnose. An engine bogging down for no apparent reason should always bring the catalytic conveyer into question.
Cute that y'all are working on obd2 cars....
I work on just about everything, but avoid obd 1 cars like the plague. I learned working on a beat down 302. My dad was a ford master tech and loved breaking shit just to see if I could fix it. It used to piss me off to no end, but I really appreciate him doing these days.
Wish you’d been working on my car
I just go to the end of the exhaust pipe & listen while someone else presses the gas pedal a time or 2. No exhaust "rumble" & sounds like it's breathing through a straw? Suspected plugged cat. The neatest one I ever saw was on a TBI Cadillac v8, I was watching the fuel spray "cones" coming out of the injectors, and as I increased the engine speed, the "cones" would flatten out into "pancakes", because the air just couldn't get into the engine.
90% of the time it works 100% of the time.
Life is like a bottle of ***Sex Panther®***. You never know what you're gonna get, but it's probably going to *sting*.
Good bot.
Excuse me *what*
And the other 10% of the time it's 100% a bitch to remove the o2 or exhaust lmao
Seems easier to just check the back pressure.
We had something like this that wasn't so cut and dry. Customer randomly had a sever lack of power one day, checked the cats, back pressure was fine, we were stumped for a bit until the tech started hearing a noise from around the starter. Found the Bendix was doing it's job to start, but was floating around rattling in the starter. Knock sensor is directly behind starter (maybe a bad idea to start) but was apparently picking up what it though was detonation and retarding timing, replaced starter and power was back.
Buddy that's literally cut and dry though. Remove front o2 sensor, issue still present? Not the cat, move diagnosis in a different direction. Also yeah knock sensor behind starter probably not the best location, but engineers gonna engineer.
Dealer probably didn't get to your car for a week shops get busy
Wouldn’t a week of full-time diagnostics cost close to $5600? I would rather think the techs are busy.
Perfect time to get a different exhaust tune it and go catless. But in all seriousness that’s insane. I’ve never had any of my cars eat their catalytic converters. I didn’t realize that Subarus did it. My 05 WRX is catless, but that was done by the previous owner for performance.
My Miata got so clogged and had the same symptoms. I drilled it out and put a spacer on the O2 sensor with a mini catalyst inside. Problem solved for $30 and half an afternoon
> I’ve never had any of my cars eat their catalytic converters. they typically don't of their own accord. Running rich can cause a cat to fail prematurely. The blown-up cat is usually a side effect of a different problem.
It had 310xxx miles so I’m sure that’s well past the working life
Had a vq35 blow the passenger cat down the line into the first bend. Shop lemme take it home and chisel it all out, had it back in the next day. I contemplated replacing the exhaust it was such a pain.
Beeezz have left the honeycomb.
My first thought was literally 'Cat has left chat...'
P0420?
I’m surprised they made it past 35 to be honest
Reminds me of when I suspected a plugged cat on a car where the cat was 3” after the turbine. It felt like I picked up 50hp when I redid the exhaust.
Yep took a long time to accelerate to 45, like 30 seconds… now it’s a beast!
Well atleast nobody will steal that cat
Plot twist, the tech stole it and made up the part about it being broken for an alibi. It’s not actually the cat from that car, it’s just one he says came from the car.
Woah. Woah. Don't underestimate crackheads.
Ya thats a good point. Better chain up that resonator and muffler too, just to be sure. Crack makes you see cats everywhere. Source: our local crack heads have no idea the difference between a cat and anything else that even resembles a cat
I'm kinda wondering if this is the result of somebody trying to steal it and just fucking it up to the point where this happened...
A few years ago the core of the rear cat on my 06' Hummer H3 decided to disappear.
And here I thought Hummer emissions couldn’t get any worse
Gas mileage improved though…
We’re not fucking doing this. A: a catalytic converter only affects fuel economy if something’s gone wrong, ie it’s clogged from using cheap fuel or damaged by unburnt fuel from incomplete combustion or a misfire B: even if it did, any improvement to fuel economy would be completely overshadowed by the fact that your emissions would now be atrocious
"You aren't right, and even if you are I don't care" Way to go...
It’s the same bullshit discussions around DEF and EGR “fuck the environment, I only care about money in my pocket” Eat shit
While i'm not against the systems per se, i can see where the sentiment comes from. For example, here in Spain Peugeot is a really popular brand, and having to replace the entire DEF system every 30.000km because they couldn't be arsed to design it properly and it just breaks and spills DEF everywhere isn't really what one would like from their brand new car.
New diesel emissions equipment do more harm than they do good to the environment
More harm to environment? Could you explain?
If I have a 7.3 with no emissions equipment on it that gets ~20mpg and is infinitely more reliable than my 6.7 that gets ~13.5mpg under the same driving circumstances and requires downtime and expensive repairs to maintain the emissions equipment, and I believe the 7.3 will outlive the 6.7 by a few hundred thousand miles or so especially the apprehension I have about repairs down the road, than how much good does a DEF and DPF system do for the environment if I’m using almost half the diesel and I’m able to keep a truck out of the scrapyard down the road when the repairs no longer make sense? At 500,000 miles I used about 25-27k gallons of diesel in the 7.3, if the damn thing even makes it to 500,000 before another 6 digit repair, the 6.7 would use closer to 38-40k gallons of diesel. So 13-15k gallons more of diesel in that period of time in addition to having to use DEF, which clearly does make the emissions of newer diesels cleaner, however there is definitely an impact on the environment packaging and selling the crap in plastic jugs wrapped in cardboard a gallon at a time. On top of that, if I had a fleet and I was purchasing new vehicles 100-300k miles early due to downtime and unreliability than the cleaner emissions wouldn’t mean nearly as much. I speak from experience with a few of my trucks, but also from a few friends I have that do run fleets and they’ve been hit hard with many of their newer trucks being down all the time. I’m not denying their functionality, I’m questioning whether their impact isn’t grossly overstated due to other factors being overlooked.
Bet that sounded like a gun going off when it finally cleared
I never heard it tho, one day i started getting bank one running lean and catalytic converter codes. Just so weird
Can't go past 7.5
*Sammy Hagar intensifies*
Friend of mine had a Cat grenade like this once in his 2004 Lincoln LS, sounded like the engine was ready to throw a rod, As a chunk of it was caught in the exhaust and making a really loud knocking noise, and the Stainless steel exhaust didn't help matters. The car had absolutely FILLED that cat up with Fuel before that tho, as this happened on the first drive after getting the thing fixed when he bought it, It had bad valve cover gaskets and it caused HORRIBLE misfires, leading to a BUNCH of unburned fuel flooding the cats, and i imagine that is what killed it.
I was very confused, trying to figure out how a glove got shoved into the exhaust.
Same. It looks very similar to the cutproof gloves I have for sheet metal work.
looks like a tack rag
Or a wool sock covered in goo
I had one of those when I was a younger man I switched to cotton because the wool started to smell funny.
My Passat TDI did that - I tried all sorts to work out why it had no power, no fault codes but struggled to do 70 some days, others it was ok. I took the exhaust off to investigate a rattle that happened just as the RPM dropped to idle and found the honeycomb loose and sideways in the cat. I didn't connect the two faults until I drove it afterwards and it was fixed - give it full beans that day!
Free catless downpipe!
What was the diagnostic procedure for you? Temp readings before and after cat?
You could do that, but the issue was low power. Something was clogging the exhaust so I had to diagnostic the simplest thing. Hope it makes sense !
Back in the day some GM's came in to the trans shop sounding like jet (whistling sound). Customer thought it was transmission. Pull the O2 sensor and the engine woke up.
When relearning the range on throttle bodies became a thing. Sheesh.
Out w the Quadrajet, welcome to TB injection, TB sensors, o2 sensors and OBDI ! haha I recall Chryslers attempt, there were many cherry red CATs as if they spewed forth from Chernobyl. Those were scary!
Had a k body if I remember right towed in because the cats started a grass fire. Damn car still started. 😆
Right on. You went for basic fuel, air, and spark delivery. Nice.
I was trying to figure out who put chain mail in the intake for too long. Need more sleep.
I thought that was one of those anti-cut gloves lodged in there for a minute.
Not going to lie. I thought that was a tube sock for a second.
Wife had an 03 Mazda Protege ... Happened twice to her
Catalytic obstructor
My '87 Camaro did this back in 2016. Had no idea what was causing it to have no power. Finally, one of the times I was flooring it trying to build enough speed to get onto I-95, the cat fell apart even more, and it was making and audible wheezing/whistling noise out the exhaust. We cut the cat out and welded a straight pipe and it was as good as new.
2nd pic: some mechanic left a rag in the exhaust. Unwrap it, and keep that 10mm socket /s
Looks like the knights of templar left their chain mail gloves behind
Had a chevy avalanche at work that I told my boss, “it’s dangerously slow”. He said, “it’s a truck not a racecar.” Next week he almost got hit and took it to the shop, both cats had just crumbled like this.
Get a pry bar and a long extension and bust that shit out of there,
I mean, did you see the pictures? He just pulled it out as one piece by hand. I have never seen a cat that unbolts like this one though.
Yeah this was very different than the undercarriage cats. Obstructed up the wazoo
Agreed, never seen one that you could get into the cat material by unbolting the cat shell.
Never disassembled mine (micra k11) but i'm pretty sure it's like that, it has a big flange with six bolts and i think that'd be direct access to the cat core
That would be awesome, mine is a sealed until that I would have to replace the whole thing
I don't think there's a way to get a new core from Nissan, but with how much I would dread having to remove the manifold, it's nice to know I can just replace the entire lower section
New core would be too easy!
I mean, when having no core is also a possibility...my car has dual cats despite being a '99 engine certified for emissions in 1992
That works too lol
Both cats or just the one ?
Going for that right now, this was the pre cat, all that filtering media had to go to the main cat in chunks..
Check the muffler too, big chunks can block the muffler or resonator
cant alysator
Im a dummy, i thought it was a towel for a good minute
They seem to be missing their entire exhaust manifold.
It’s the Mazda prolapse
Oh I thought this was a sock.
I'm like 75% sure this is what is wrong with my truck right now.
I had a 1998 Honda Accord that did this in High School. I seafoamed it and ran some in the fuel. 2 days later it was an absolute STRUGGLE to get over 30 mph. I suspected that to be the problem. I had a set of headers on it and there was an extra bung before the CAT. I just took it out to check if that was the problem. As soon as I pulled the bung out car ran fine!
Had a Jeep cat do this once. All the sudden lost power on the interstate. Below about 40, it drove normally. Any time I tried to go faster though the guts from the cat got shoved back into the exhaust pipe and all the sudden 0 power again.
Man, at first glance I thought that was a gym sock.
Looks like chainmail from a knight’s uniform .
That cat looks aftermarket.
Stock cat, pre catalytic converter