Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello, depends on what code(s) are setting and if you are having an issue with the upstream precat convertor sensor or the catalytic monitor sensor they operate differently
Ok the drivers side(bank 2) upstream oxygen sensor is not reading properly. its setting a code so the check engine light is on. Whats the code P0174/lean. rich code? heater circuit. need some more information please.