help po138 po139

Question

i have an 2001 mercury villager that is throwing codes po138 and po139 I have changed both O2 sensersand my CEL came back on with the same codes can you tell me what else I should do and where to look

Answer 1

If there are no wiring issues with the oxygen sensor, the car should be checked for intake air leaks, and exhaust gas leaks. If there are not leaks check fuel pressure and check for faulty fuel injectors