I bought a 98 Taurus with a bad engine (timing chain problem). I replaced
the engine with a 47K mile engine and all was well except for an SES and
code P1132 (fuel mixture, bank 1, upstream O2 sensor). I checked for vacuum
leaks, air inlet restrictions, exhaust leaks, and replaced the PCV valve.
I reset the code and it came back after a few minutes of driving. I cleared
it several more times and couldn't find anything else wrong, so finally I
swapped the two upstream O2 sensors and reset the codes. This time I got a
different code, P1152, which is the corresponding code but on bank 2 rather
than bank 1. The bank 1 code did NOT return. After clearing the code
several times and getting repeatable results, I thought I had isolated the
problem and bought a replacement O2 sensor, a Bosch OEM type sensor p/n
13117, and installed it in place of the "bad" one. With that sensor, I soon
got a P0155 code which indicates an HO2S heater circuit electrical problem.
Thinking I had bought a bad sensor, I replaced it with another new one,
cleared the code and got the same P0155 code back again. I cleared it a
couple more times and it kept coming back. With the idea that maybe I
damaged the wiring somehow I put the original sensor back in the car and
cleared the code. (note: both Bosch sensors I removed were black with soot,
unlike the light tan original sensor). Sure enough I now get the P1152 code
back again, but no P0155. I was tempted to just go to Ford and buy an OEM
sensor, thinking that would solve the problem, but Ford wants $144 for the
sensor, which is a pretty expensive test if I am wrong. Bosch also has a
Universal type sensor that is a little more expensive than their OEM type,
but I can't be sure if that would be any better, and I don't want to just
start throwing money at this problem.
Is there something else I am missing here? Any suggestions on how to
proceed would be greatly appreciated.
Thanks in advance,