Rollin'ES3

Hey guys my misfiring machine is back with a vengeance

The misfiring issue was corrected and I replaced all 6 coils to avoid problems later on.....(but we all knew something was bound to happen)

Now I'm getting the infamous 420 code. But this code came only after this whole misfiring thing. So my guess is that while it was running with that misfire, unburned fuel and etc went into the cat --Bank 1--. Now My question is do you guys think its the cat thats bad, or the 02 sensor for bank 1.

Ive done searches and Im going to check the ohms on the 02 sensor and see if its within specs. and make sure its not jumpin around all over the place.

Any suggestions or ideas on this situation would be appreciated. I may give in and try the 02 sensor bypass trick if it is the cat.

Thanks in advance to all

dallison

damn, you replaced all 6 packs????

Rollin'ES3

Yeah, all 6 of em.

llcoolpass

it could be either . you need to proceed to diagnose it. like you said, check the 02 response, both front and rear bank, and if error, replace it/them and then reset ecu. and drive through loop. see if any codes come back. ideally, you can see the osciloscope reading of all the 02 sensors to see which ones you want to replace.


02 sensors are 80K miles maintenance items. if in doubt, change.

03 ES

try the cheaper o2 sensor before you go and buy the cat...
even if it is the cat, at least you took care of the o2 sensor so that wont go up as well...
its all about planning and doing preventitive maintenence