I’m replacing my cat converter. I lost all power at acceleration. After a vacuum test at 21 inches at idle and about 4 to 5 inches st about 1800 rpm I decided to check cat converter. Yep. It had a huge exhaust restriction. The honey comb element was in a million pieces in my universal California Walker 81122. I got a new one but I wanted to see if anybody knows how I should check the systems to make sure my new $350 cat doesn’t go bad again! Car was running perfect. I mean there was a very small vacuum line that want connected in front on the bottom end of the carburetor, but after I hooked it up, the car did not seem to idle better or even worse so I figured it was no big deal. I’ve put about 45k mikes on my rebuilt stock 3.8l and it ran beautifully all this time. Until about 3 months ago when I noticed my smog pump siezed up and snapped the belt off. I read it was not a big deal but I think I also read somwhere if the smog pump is deleted I run the risk of messing up my cat. Could that be what made my cat fail bc, like I said i ran like a wife that knows her place in the household, like a kitty cat, for about 40k miles with no issues and about 22 mpg.
Cat Converter Stock
- Thread starter JayInLA
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It could be, if the car uses a 2 way cat it absolutely needs the smog pump working to keep the cat lit.
I've seen CATS clog up on recently made cars that have no Smog Pumps but then again as mentioned above could be the type of CAT and what it needs. A.I.R. System shot like a 6 sec burst of fresh air into the CAT before you started the car if I remember right.
Modern cars with air pumps only use them to light off the cats. Run them a little rich at startup so unburned fuel hits the cat, air pump delivers fresh oxygen, and you have ignition. I think the C5 runs the air pump something like 90 seconds? If a car was 2 way, I believe they ran a little rich factory and again used that oxygen from the air pump to light the cat. So if one puts a 3 way where a 2 way goes, I could see that being problematic as well as there are 3 sections to that brick and you'd only be effectively using the 1.
G bodies use 3 way cats, but they are old style 3 way cats than require oxygen pumped into them from the AIR injection pump for complete catalytic operation. Modern cars use newer style 3 way cats that generate their own oxygen.
Some engine options injected air into the exhaust manifolds first during cold engine operation. Then once warmed up switched to injecting air directly into the cat converter. Some engines just injected air directly into the cat converter.
Other thing is that rich fuel mixtures will ruin cat convertors, which is why CCC and EFI were developed. Leaded gas will also ruin cat convertors.
Some engine options injected air into the exhaust manifolds first during cold engine operation. Then once warmed up switched to injecting air directly into the cat converter. Some engines just injected air directly into the cat converter.
Other thing is that rich fuel mixtures will ruin cat convertors, which is why CCC and EFI were developed. Leaded gas will also ruin cat convertors.
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