I recently replaced the converters on my 2009 Traverse. It's been almost a month and I now have a P0420 for catalyst efficiency pop up. Should I look at the O2 sensors now or what? I also had P0497 resolved within the past week, could this be a cause?
Curious- if youre in a state that follows California/NY type emissions- were the CATS, when replaced have to be replaced with OEM cats that meet CA emissions specs.
If you replaced with generics---- that may be something to look into
The car is in North Carolina but it came from NY. I looked into the OE cats going on info that there were two different sets of cats based on the NY,CA emissions, but there was only the one set. I used Walker Ultra series direct fit cats and they worked for almost a month before the 420. I had an issue with the P0497/P443 code that actually turned out to be the evap valve on the intake. Now the posted 420 and last night P0430 showed up (the 420 had been cleared for almost a week). Possible it could be the O2 sensors? They were replaced some time back while the old cats were on the car and other issues were being addressed.
Possible sensor but my money is on aftermarket cats not working on a CA. emission's vehicle.
OEM cats are the only reliable replacements on CA emissions vehicles.
Watched my brother go through that on a Impala CA emissions car with aftermarket cats