P0420 Code Issue
#21
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mine is ontop of a u shape pipe so it doesnt hang down or anything. my space ontop is limited but i may have enough space..its 10 degrees with no garage here this week so i cannot check yet
#22
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,217
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I know a guy who for a small fee could be willing to tune out that P0420. Shoot me a PM if interested.
#28
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Although the P0420 code refers to cat converter efficiency, there are several things that can trigger the code. Do you have any leaks in your exhaust system? How do the wiring harnesses look going to both O2 sensors? Since you say your mileage appears normal we'll rule out a faulty injector as the cause for the code. If the exhaust system and wiring harnesses check out okay have your mechanic monitor and compare some real time data on both O2 sensors using a Tech II (or equivalent) scanner. Speaking of sensors, what brand did your mechanic use? A lot of aftermarket sensors don't replicate OE parameters and can cause problems right out of the box. If the readings from both sensors are too close to being the same it will trip the code, but it is the sensor that's faulty - not the cat converter. If the sensor used is anything but an AC Delco or Delphi that may be the whole problem.