Hi,

If anyone can provide me insight I would greatly appeciate it. My service engine light came on, mechanic checked codes and came back with two bad oxygen sensor codes one for front and one for rear (P1185, P1193).

My question is that given that there are four 02 sensors, do the codes indicate which ones are bad or do all four have to be replaced (truck has 111,000 miles and for the six years I have owned it I haven't changed any of them).

If anyone has any idea as to which ones need to be replaced and the parts numbers I would greately appreciate it as I just failed my emmissions test and need to fix the problem quickly.

Thanks,

Mark