Aurydas

Hello everybody, I need help with my Nissan. I dont know whats wrong. I get Check Engine Soon light on every 100miles with code P0138 and P0139 (O2 sensor slow response and O2 sensor voltage to high) What I did I just flashed cooling system replaced houses. 15 min later light was on. After that I changed all O2 sensors with originals from dealer reset ECU ligth came back with same codes, than I cleaned MSF sensor reset ECU ligth came back, changed oil, air filter checked MAP sensor seens to working good, light came back. Van Runs great no problems no smoke. Im out of ideas....anybody knows whats wrong????

MrOldLude

In the manual for my truck I can't find codes for P0138 and P0139. For your car, do the codes correspond to pre-cat or post-cat sensors?

Though for me, if the ecu detects too high voltage, the check items are:
Harness and connectors (the sensor circuit is open or shorted)
The front heated oxygen sensor.
Fuel Pressure
Injectors
Intake Air leaks

Sorry I can't help too much.

__________________
Mr. Pete
1997 Hardbody 4x4
1989 Prelude 2.0 Si

Aurydas

Thanx Guys, I found the problem it was broken wire in connector, not big deal I fixed it and no more stupid MIL light.......