Not on the Mustang, but the generic codes should be the same for my '97 Taurus. I have a P0430: Catalyst System Efficiency Below Threshold (Bank2) MIL that keeps coming and going. Does that mean an O2 sensor on the Bank2 side is bad or the cat is plugged/bad? The car has 145,000 miles, so I'm think'n the later, but I'm not sure.
Any other problems this could be that I'm not thinking of? Sorry for the off topic
Any other problems this could be that I'm not thinking of? Sorry for the off topic