deanbrown

I have a leaky exhaust system - I just changed all 4 O2 sensors and I still get the same codes (P0420 and P0430), and I can feel it blowing out at the rear joint just behind one of the cats, and it seems to be blowing out of the cats somehow, though its hard to tell as the shield is in the way.

What are my options? Should I get a whole new system with cats too, or do the cat never leak themselves? I'm sorry but I have no experience with cats (only patching up leaky rusty pipes, for which I find stainless steel tape plus a bunch of hose connectors to be a good bet).

Thanks for any tips. Its a 96 LS with nearly 200K miles.

ps Is there some chain that only does exhausts?

jcrome04

As far as cats are concerned If you're in a place that does NOT do emissions I'd straight pipe the 3rd behind the O2 sensors. and replace the 2 before them. They will rattle around when they need replaced.

Find a good indy exhaust shop to replace your entire system. If you want it loud, go with 2 1/4" piping to an X-pipe to mufflers of your choice.

If you want to keep it stock, just have them fix the leak. They shouldn't charge you to look at it, and the heat shielding doesn't really serve a purpose so it is not a necessity. The piping behind the shield is probably pretty rusted out. Mine was at about 140k miles.

skperformance

iTrader: (6)

Always keep a heat shield it really is keeping heat out of the interior of the car.
Straight pipe the third?
Were not going to get on the car having a 3rd cat again ?
Find the leak at a muffler shop and they will tell you what to replace. A leak means a sensor is not going to work right.

deanbrown

Thank you gentlemen.

Yes in NJ they inspect emissions, and that's coming up in July. It might not fail though, if I reset the light just before the inspection, but I think I have to get it fixed soon.

If the cats are in good shape, how much should I expect to pay for a replacement system?

jcrome04

So is the 3rd thing in between the Y-pipes just a resonator? I always thought it was a cat.

PureDrifter

iTrader: (10)

on MOST cars it is a resonator.
on some cars, hard to tell which ones, it is a cat.

jcrome04

Hmm mine was rattling around a bit I assumed it was a cat, either way I just had mine straight piped.

Bradster

This should help.