Let's talk catalytic converters

[3pt1lumina]

As you may remember one of my previous threads, my Lumina doesn't idle at all. I've replaced the TPS and the IAC (again) and the problem isn't solved. Then the smart guy I am, I decided to listen to the car. Now, the car has always had a pretty big exhaust leak. Well, it's definitely worse. It seems as if it's coming right from the catalytic converter...

 

Okay so my questions are:

-How can you tell if one is bad?

-What do you replace them with? (if I am replacing, I'm going high flow cat)

-Will it cause a bad idle issue?

 

My car still performs excellent. Infact, with the new TPS it is noticeably faster. It just doesn't idle. I've tried an idle relearn as well....numerous times actually. This is my next guess here.

[Prospeeder]

Smell of rotton eggs would be a dead giveaway of a bad Catalytic converter, or if it glows red or rattles

[Crazy K]

B I N G O ! My pipe cracked between the converter and the engine. It cracked at the top along a seam in front of the converter. Also... you might as well replace the dounut that goes between the manifold and the pipe while you are down there.

[3pt1lumina]

It sometimes smells like rotten eggs but only from time to time. The exhaust seems to be running hotter than usual, so next time I let the car run I'll crawl under there and look and see if it's glowing. I can't really duplicate the smell it makes into words.

 

Oh yeah that crack on the pipe on that seam, it's been there since before 10/02 when I got the car. I've doctored it a couple of times, but this might be the end. If the cat is dead, I'm doing new exhaust from the manifold back, potentially dual exhaust. My exhaust is dead, it's been dead for awhile now. I think it's time to actually do something.

 

Problem is, if I spend a ton of money on this and it doesn't solve the problem, I'm going to be a really unhappy dude. But if it needs to be done, I think I'll just do it come spring time.

[Crazy K]

well you don;t have to replace it all... if you are hurt for money, just repalce the converter, and run a pipe forward so as to cut it off to infront of the crack.

 

As for dual exhaust, you could do what I plan to, which is a used set of mufflers with spliter pipe and should be a direct fit and splice

[Prospeeder]

or you could put a Straight pipe there if theres no emmisions

[3pt1lumina]

or you could put a Straight pipe there if theres no emmisions

 

Stupid NY... wanted to do that (did it to all of our classics) but it'll never pass emissions. And I really should replace the entire system as it's pieced together something fierce. It is ready to fall off in the back (has 2x, rigged it both times to pass inspection).

 

So would this bad cat make the car not idle worth a shit but still perform okay?

[Crazy K]

possible, it would at least be a factor.... but it does need to be done.

[Prospeeder]

make a video of what your cars doing

[mfewtrail]

If your catalytic converter has failed and stopped up, then your car will feel noticeably sluggish when you try to accelerate. If you car accelerates fine and you don't notice a loss in power...the cat isn't clogged.

[Crazy K]

video please.

[White93z34]

when the cat went on the camaro the car just got noticeably worse in accelerateing and overall performance till one day on my way to class the car was limited to about 40mph on the highway then it just stalled out and woulden't restart. i had it towed into the shop and i gutted the cat, and that was it for that problem.