Hello,
My name is Carlos I am new to this forum and I need some suggestions. My check engine light turned on. After scanning it at Autozone the three codes P1166-P1167 & P0128 came up. The O2 sensor (P1166) I had already replaced it about a year ago its pretty expensive. But they suggested replacing my Engine Control Module (ECM) now I really dont have much to replace the ECM theyre about $400. Should I replace both my O2 sensor and the thermostat and hope for the best or just replace my thermostat and keep the same O2 sensor?

Thank you,
Carlos

 

P1166& P1167 are electrical faults in the AF sensor heater circuit. The fault could be sensor (unlikely since replaced), connector, wiring, or PCM (ecm). Electrical testing of heater circuit should be performed next. These tests can be performed w/ volt-ohm-meter or test light.

The test can be simply checking for power and ground on the two heater wires at the AF sensor connector (harness side). If either is missing, test at the ECM connector (harness side) are necessary to isolate the fault to wiring/connector or ECM.

good luck