Replace exhaust manifold gasket?
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Intermediate
Joined: Oct 2007
Posts: 30
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From: Houston TX
Replace exhaust manifold gasket?
My girlfriend's 2000 coupe is throwing P0430 codes (catalyst efficiency below threshold, passenger side) so I hooked up my ELM327 OBD-II scanner and took readings from the O2 sensors on my drive to work.
Here are the results:
If anyone has any experience with this, does this look like a bad catalyst or an exhaust leak, or maybe even a sensor going bad? I bought a new manifold gasket because that was the least expensive possible cause of odd data, but I'd rather be sure that's the problem before I go to the trouble of replacing it. I'm assuming the code is being thrown because of deviances in the passenger side downstream reading like the one around 930-950 seconds.
Here are the results:
If anyone has any experience with this, does this look like a bad catalyst or an exhaust leak, or maybe even a sensor going bad? I bought a new manifold gasket because that was the least expensive possible cause of odd data, but I'd rather be sure that's the problem before I go to the trouble of replacing it. I'm assuming the code is being thrown because of deviances in the passenger side downstream reading like the one around 930-950 seconds.
Last edited by Eep; Oct 13, 2007 at 11:53 AM.
Thread Starter
Intermediate
Joined: Oct 2007
Posts: 30
Likes: 0
From: Houston TX
Just a little extra info: The period shown starts just before my arrival at work and has the car coming to a stop and idling for a while, returning to closed-loop. Other info, the car has about 65K on it with just over 30K on the engine (apparently the original sucked down some water, so if they didn't replace the cats then I suppose temperature shock from being dipped in the puddle that drowned the engine could have damaged one or both). I do feel like I hear a bit of a click, so there could be an exhaust leak somewhere in the line (why I bought the gasket), but I tried listening around with a section of hose and just using my nose to sniff out a leak and didn't find anything.
