Contour Enthusiasts Group Archives Forums General Troubleshooting Both P1151 and P1152?

Hello folks. I have CEL P1151 and P1152 for my 97 contour/95k. One indicates lean but another indicates rich. Does this mean a dead upstream bank #2 O2 sensor?

Problems that only affect one bank are things like a sticking fuel injector, a UIM or LIM gasket leak, or a broken IMRC linkage on that side.

If only one bank is acting up and the O2's are original, it usually is the O2.

1151 lean bank 2, 1152 rich bank 2. This could be one of two things.

One code is old and no longer valid. Clear the codes and retest.

If only one code comes back after reset, swap the upstream sensors between banks. If the problem stays with the sensor, replace it. If it stays with the bank, check the harness and let us know if itâ??s lean or rich.

Since bank 2 canâ??t be lean and rich at the same time it sounds like a harness problem. Possibly a short from brunt insulation.

Since you donâ??t have a lot of $$ to spend, switch the upstream O2s between bank 1 and two. Reset your codes and retest. If it still says bank 2 lean/rich (at the same time) fix the harness. If the problem jumps to bank 1, buy a new O2 sensor.

jeff

I am think it's the harness problem because the CEL has gone now. I am going to reset the computer and waiting for it comes back next time.

Thanks anyway.

I reset the computer and clean the connector. The CEL came back as P1151, and it has gone again after several driving cycles. I believe it is a good idea to switch the upstream sensors to test whether the sensor is gone, but it seems too much work. Any other idea?

Final update. It turned out to be the O2 sensor. The CEL does not come back after I replaced it two weeks ago.