Which engine and how many miles? Original cat? Is the upstream O2 cycling and is the downstream O2 steady?Can somebody help me out with this P 420 code that popped up Is it the O2 sensors? I have a 04 focus se
Replace the rear o2 sensor if its never been done. If it's not that, and your car has high miles, it's probably the cat on its way out.Can somebody help me out with this P 420 code that popped up Is it the O2 sensors? I have a 04 focus se