Litemup
10-04-2007, 07:58 PM
I recently had my car inspected and didn't pass emissions. The code that first came up had to do with the catalytic converter gone bad. So fine I never changed them and I currently have 174,000 miles on my 96 Impala so I purchased some magnaflow cats. Cats were installed, mechanic cleared the check engine but when I started my drive home the check engine came back and 2 minutes after it came on it started flashing! So I turned around and went back to the shop. Mech pulled the codes P0171 and P0300. He advised that one of my 02 sensors went bad, and I have a multiple misfire code. I determined that the O2 was actually bad by swapping sides clearing the codes and driving again. The P0171 came up on the other side, and the P0300 came up again. Could a bad oxygen sensor cause a misfire code? I put in new plugs and wires and changed the pcv valve. I also put in a new fuel filter. Any help is greatly appreciated.