p0420

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JWO101
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Hi Guys new to the site want to give you a try,it's a goody.My wife has a 2001 chevy camaro,3.8L,102,000 miles. we keep getting the code P0420 which is catalyst below range left bank.
I replaced the converter at 83,000 (had come apart inside) with a high flow universal at my local muffler shop.The factoy one cost $550 plus my old one,the muffler shop cost $175, the walker one cost $358. Ok here's where the fun starts. Everyone told me that it had to be torch welded because of the material the factory pipe was made of. Ok i'm a mechanic but I don't do exhaust for the reason of I don't have a lift yet. Of course I had to take it back several times for the weld breaking. And allowing o2 into the system and being noisy. The p0420 continued to show up all through this. About 2
months ago I order a replacement from walker muffler (the replacement goes from manifolds to the next section behind the trans. Of course it was made wrong and wouldn't fit. While I had it off I noticed that the 3" section of pipe going into the converter was steel , not alumnized,so I welded it with my mig.I had already replaced both o2 sensors in the manifolds and the downstream one also.Now I have an airtight system,4days later the light came back on with a p0420. Any ideas?
Jan 9, 2007 at 2:50 PM
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CARUNDELL
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[quote:e58c5006e6="jwo101"]Hi Guys new to the site want to give you a try,it's a goody.My wife has a 2001 chevy camaro,3.8L,102,000 miles. we keep getting the code P0420 which is catalyst below range left bank.
I replaced the converter at 83,000 (had come apart inside) with a high flow universal at my local muffler shop.The factoy one cost $550 plus my old one,the muffler shop cost $175, the walker one cost $358. Ok here's where the fun starts. Everyone told me that it had to be torch welded because of the material the factory pipe was made of. Ok i'm a mechanic but I don't do exhaust for the reason of I don't have a lift yet. Of course I had to take it back several times for the weld breaking. And allowing o2 into the system and being noisy. The p0420 continued to show up all through this. About 2
months ago I order a replacement from walker muffler (the replacement goes from manifolds to the next section behind the trans. Of course it was made wrong and wouldn't fit. While I had it off I noticed that the 3" section of pipe going into the converter was steel , not alumnized,so I welded it with my mig.I had already replaced both o2 sensors in the manifolds and the downstream one also.Now I have an airtight system,4days later the light came back on with a p0420. Any ideas?[/quote:e58c5006e6]

Hey jw!
Before we go any further ....... do you have a scanner or labscope so you can graph that post cat O2? I say this because we need to verify the signal being sent back to the pcm. pm or email me

Chris
Jan 9, 2007 at 3:33 PM
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JWO101
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Now it's even better,my actron reader quit working.
It's been a good one ,lasted 7 years,time for a new one.Been looking at an x-ray, any thoughts?
Jan 9, 2007 at 7:00 PM
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