Anybody hear of this or try this? I've seen the Sea Foam method online where people have run it straight into the throttle body and it produces a bunch of smoke and supposedly cleans the cat. I've also seen where people have run laquer thinner in the gas tank and one where people have sprayed carb cleaner into the exhaust test plug before the cat. There are also combustion cleaners out there that are said to help.

I'm not comfortable running anything other than gas through my system, but am considering the carb spray into the test plug. I may also pull the cat and soak it in detergent to clean it out which I've also seen online. I figure its worth a try on an old cat and if it doesn't work I can always install the new one I have.

I tried running my car at high rpms for a long drive (per pierce) and it did reduce my HC emissions a bit so thinking I might benefit from cleaning my cat if that's indeed possible. I can imagine the build-up blocking the catalysts in the cat and making it run less efficiently.

Thoughts?

 

I've run fuel injector/system cleaner. I honostly don't feel a difference nor smell a difference.

Seaform is meant to clean the carbon deposites out of the engine.
The cat is another story. They are design to grab though a chemical attraction.
That's why they use platinum palladium and rhodium in catalytic converters.
I'm not sure if you can clean them out.

 

You can't clean them you can only gut them. Usually the O2 sensor starts to fail causing emission issues. So if you replaced it then the cat is pretty much shot. By the way cats usually get plugged which then will overheat. So if you suspect this just go get a new one they are not that expensive. I've replaced 2 in our 89 740 . The orig. one lasted to almost 200,000 miles and the replacement is now at 340,000 and still OK.

 

our 87 240 went about 400k miles on its original cat til it needed replacing.

most other cars I've had needed a new one around 250000.

I'm in California, land of mandated smog testing.

 

Hi guys,

The code (per a mechanic I trust) is once again indicating an issue which he says means I need to replace my catalytic converter. I have a 2004 S-60 with just over 100,000 miles - which seems low for a Cat Conv to go bad but of course it's past warranty. By the way the code came on periodically last Fall but went away the entire winter - until just recently when the weather warmed a bit (which could be a coincidence).

I'm very handy but have never attempted exhaust work because I've always assumed it's a rusted mess down there and I'd need a torch and related welding skills. Is that true or a misconception from the pre-stainless steel days?

Any thoughts/suggestions are appreciated as I'd love to reduce the nearly $1,000 charge for the mechanic to replace it with a non factory Cat Conv.

 

wait, what? s60? wrong section of this Volvo Forum. This here is 1975-1993 240, 1982-1992 740, and 1991-1995 940. 4 cylinder, rear wheel drive last of the classic volvos.

for a 240/740/940, a quality aftermarket cat like a Magnaflow is about $100 ($200 for California/NY spec cats), and a good indie muffler guy can weld it in right quick neat as can be. a Volvo brand cat, if its still available is $$$$$. Magnaflows work just fine.

I'm surprised your cat is gone at 100k miles. have the oxygen sensors been checked ? (I think you have two). do you drive your car briskly, or do you baby it always, never rev it? it needs to be run hard and revved up. 65 on the freeway in 3rd gear for 10-15 minutes, get the exhaust nice and hot, burn off any crud.

that might just fix your cat.

 

Sorry for the misplaced post - I just did a search on Catalytic Converters and came across this thread. I will definitely ask if the oxygen sensors could be bad - haven't had those replaced. Thanks for the insights!

 

My first 240 had about 250K on it and passed smog on the original cat no problem. I crashed it less than a month after smog and still have that cat (along with the rest of the car!) so I might try that one first before going with a new aftermarket one. Why?? Here's the reality about cats...

Original factory catalytic converters are mandated to last a certain time/mileage -- I believe it was 100K and 10 years at one point but I think now its gone to 7 years. WHY is this important?? Original catalytic converters have more catalyst (precious metals) in them so they can last that long (and are therefore much more expensive.) Aftermarket cats don't have nearly the same amount of catalyst (and therefore much cheaper) and WILL NOT last nearly as long. They give you a 1-3 year warranty at best. That's why I'd like to stick with the original factory catalytic converter as long as possible. With a properly tuned engine, the stress on the catalytic converter is much less and they will last a really long time.

Everyone should understand this when just swapping a cat for an aftermarket one and expecting the same longevity. I've heard people replacing their cats every 3 years once they got on the aftermarket cycle. Unfortunately, with older cars the OEM cat is NLA.

 

this is why California mandates a CARB certificate on any replacement cats... they have to be made to the original spec as people were slapping on the cheapest junk they could, and they'd last a year, then fail at the next test 2 years later. This certificate just about doubles the price of replacement cats, c'est la vie. I figure something thats going to last another 20 years and 250k miles is *worth* $200.