Cleaning a cat

[Shaun @ Tru6]

A friend has a 98 Tacoma with 230K miles, I-4. He thinks the cat may be clogged, CEL is on. Any additives available that would clean it while driving?

[slodave]

Not really.

MAF can be the culprit... I spent 4 odd years tracking down a code that kept pointing to the cat or o2 sensor. Finally found an obscure post that mentioned the MAF. Turns out a mechanic did not put the air cover back on correctly and dirty air got past the filter and coated the MAF sensor. Cleaned it, reset the OBD and it's been trouble free for a few years now.

[gearya]

How hot is it?

And BTW cats are notorious killers of wildlife. Shoot a crossbow bolt through it and be done.

[GH85Carrera]

Pet shampoo, water and some welding gloves is all you need to clean a cat.

[bell]

Originally Posted by GH85Carrera

Pet shampoo, water and some welding gloves is all you need to clean a cat.

The welding gloves are key........lol

[Brando]

Don't forget to trim their claws before hand - all 4 paws!

Originally Posted by bell

The welding gloves are key........lol

[john70t]

A cat is basically an oven or thermal reactor:
O2 + fuel + platinum/palladium =makes heat combustion to split the stray molecules that aren't burnt in the combustion chamber.

Test:
1). Put an infrared thermometer on the tailpipe after driving a bit.
If working- It should be 50-100deg hotter downstream IIRC.
If not- Both temps will be the same.

2). If it's clogged- Performance off the line will be good, then start to fade as back-pressure builds up in the tailpipe.
(remember that no air out equals no air in )

I've been told cats can possibly be cleaned by super heating (baking in oven or 'italian tuneup' style), but the thin platinum/palladium surface will eventually wear off.
If silicates from RTV gasket sealer usage have coated the surfaces, there's zero chance of revival.

There are also cheap back-pressure testers before $pending money, but the code could just be a bad O2 sensor/wire.

[GWN7]

I knew I took these pictures for a reason....... 98 Hyundai wouldn't develop full power. Probable causes: MAF (cleaned with brake cleaner- no difference -wasn't dirty), low fuel pressure (bad fuel pump or blocked fuel filter) or blocked exhaust.

Picture 1 is the remains of the front portion of the CAT. It had collapsed and was blocking the flow.

Picture 2 shows the inside of the CAT and the wire mesh that holds the secondary portion of the material behind it.

Your buddies CAT could be the same way

I scrapped the car.

[MT930]

[Crowbob]

The best result I have EVER gotten about cleaning a cat was when it was the girlfriend's cat v skunk.

Not my problem.

[fastfredracing]

Once it is off, I have found this a really effective way to clean one out

If the vehicle is suffering from loss of power, and you suspect the convertor is clogged, you can either remove upstream 02 sensor/sensors, or loosen the head pipe, or loosen a flange in the exhaust in front of the cat, and drive it to see if performance returns.

[fastfredracing]

Also , if you have access to a scanner that can read live data, the 02 sensor after the cat should not be nearly as active as the front sensor, if the cat is working correctly .

[Flat Six]

Hey Shaun, a replacement cat for a '98 Tacoma is around a hundred bucks . . . not an option?

[asphaltgambler]

Originally Posted by gh85carrera

pet shampoo, water and some welding gloves is all you need to clean a cat.

exactly ^^^^^^^^^^^^^^^^^:d

[Shaun @ Tru6]

Originally Posted by Flat Six

Hey Shaun, a replacement cat for a '98 Tacoma is around a hundred bucks . . . not an option?

That was my suggestion. He thinks that he'll have to put a whole new exhaust system on if the opens up that can of worms.

[faverymi]

Originally Posted by Shaun 84 Targa

That was my suggestion. He thinks that he'll have to put a whole new exhaust system on if the opens up that can of worms.

Shaun if you cut the old cat carefully and use a clamp system you should be OK.

I get that welding that old rusty piece could turn into a full exhaust very fast.

[strupgolf]

I've got the same problem. 2002 buick, 3800v6. It's a great car, seats 6, gets 32mpg hwy, hugh trunk yadayada. My cat was clogged and filled with crap. When I go up a hill in overdrive, it wants to buck, cough. On a level road it's just fine. On a hill, give it gas and the cough goes away. Anyway, the computer readout said bad cat. I replaced it, $125 bucks, just cut the old one out. The problem is, the cough is still there. I just live with it because its not a big deal for me. But now I'll have to look elsewhere, maybe a vacume line bad, or, does my car have a MAF, I dont know, it is fuel injected. Good luck.

[john70t]

Also check for a blocked muffler.

I once had a new (1.5 yo) Midas muffler rust and completely clog.
Car started to drag.
Heard a loud pop, and then car ran like a roaring tiger.
Muffler had been blown off tailpipe.
Another Midas shop charged $45 to replace because of a 'non-standard adapter pipe' used.
"Full lifetime warranty" my butt.

[GH85Carrera]

My mom drove a 1966 Oldsmobile Delta 88 they bought new for many years. They replaced the factory muffler with a Midas after the OEM one rotted off. She kept the paperwork in the glove box. Every few years it would rust out because she did a lot of short trips. They would replace the entire system and present her with a fat bill and she would hand them the paperwork with her lifetime free replacement. The manager would mutter and fight it but she would just ask to talk to the regional manager. She got numerous free exhaust systems from them.

They kept thinking they had a dumb old lady and could stick her with a nice new POS exhaust. She would just smile and let them replace it all (for free.)