OK, I scanned my computer for codes because the SES light was on. I was given the code P0420, and is that on the passenger side or the drivers side? I was gonna clear but decided against it because if I took it to the dealer I wanted it in there. Well, the light went off in about 3 days. I drove for another 2 weeks and it came back on. I have another problem and that is I have a misfire on cylinder 6 that is intermitent and causes a very rough idle. Anyways, I just got my A/F gauge and I installed it on the passenger side front O2 sensor. The gauge does not work, and I know it has power, ground and the signal wire is connected because I got harness from LS1speed. Can the O2 sensor be causing my A/F gauge not to work? On the misfire I only had the one code. Today while tinkering with it while it was running smooth I pulled of the number 3 wire and the number 5 and could not get it to produce the same idle. I put those spark plug wires back on and then disconnected the passenger side coil packs from the harness. That produced the exact same rough idle that I have been having. Could someone please give me suggestions as to what they think the problem may be. I don't want to take it to the dealer because they do more bad than good and keep the car for a week or so and I am stuck with out a car. Thanks.

 

Well, I'll just tackle the first question. Bank 1 = drivers' side. P0420 = Catalyst System Efficiency Below Threshold (bank 1).

 

OK, thanks, now that I know that the problem is on the drivers side, is there any way that the drivers side O2 could cause problems with the passenger side. Because I don't see why the A/F gauge would not work. Thanks.