check engine, code said O2 sensor- replaced- now code 'pending' low voltage P0137 1,2

so now what? thanks

Clean the MAF, run some injector cleaner in the tank and don't use the cheap gas. Clear the codes and see if they come back.

Great thanks and I even wondered if the 93 was not really 93 with gas prices so high

There are 2 O2 sensors. Did you change the correct one?

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Unless the station owner is shady i wouldn't worry about that. The lower octane gas will cause problems with the M111, so before you spend tons of money replaceing the O2's try the above. And yes there are two O2's bank1 and bank2.

ok so yes, we did change the correct one
tried the injector cleaner and the maf cleaner
hmm did not work- THEN my son noted when he made a turn over a bump the warning went off then back on- so he said; electical 'short' or something.

today he spent hours tracing the entire electrical system for me-- and as of now we think that was the problem, drove and no O2 code, no codes pending----so yep maybe did not need that sensor in the first place with the first code, but we are not pro's and bottom line for me- I still think I saved much $$$ if I'd taken to dealer---in my experience who would have replaced just about everything including 'another' wiring harness

this forum is great, thank you all and the administrator, this is not the first time i've asked and gotten valuable advice.

Was there oil in the O2 sensor harness?
Take a look at this service campaign

Attached Files

SC Cam solenoid M111 M271.pdf (459.1 KB, 976 views)

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thanks, i will ask my son-- if yes we will follow up---

Nice job finding the problem glad it all worked out for you.