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by Baer1964 » 01 Sep 2010, 19:29
by misha » 01 Sep 2010, 21:49
by FCPGroton » 02 Sep 2010, 00:24
by Baer1964 » 02 Sep 2010, 12:26
by misha » 06 Sep 2010, 01:00
Baer1964 wrote:If you connect front harness to rear sensor the black smoke goes away.
by Baer1964 » 06 Sep 2010, 21:30
by misha » 06 Sep 2010, 23:44
by t5ftw » 07 Oct 2010, 22:06
Baer1964 wrote:I am working on a 1998 Volvo S70 with a 2.4L nonturbo. I replaced the front oxygen sensor(customers request). The car was getting a po130 code and black smoke out the tail pipe. After replacing the front sensor and turning off the check engine light, the car ran ok. Soon afterwards engine light came back on with po131 code. This time I checked the live data and front o2 sensor was running about .310 volts and the rear sensor was reading 0 volts. I replaced the rear sensor and it is still getting 0 volts. I swapped the wires, connecting the wiring harness for the front sensor to the rear sensor, and rear harness to the front sensor. Now front sensor reads about .610 volts and the rear still reads 0 volts. This tells me both sensors are working, but the ecm is not seeing a reading on the rear harness. I unplugged the ecm and ohmed the wiring and all wires are good. I hate to just say bad ecm. Can some one advise me on a way to check this any further and why am I not getting any voltage reading on the rear O2 sensor harness.
by xtrattitude4u » 07 Oct 2010, 23:15
by ziggy55 » 08 Oct 2010, 00:27
by t5ftw » 08 Oct 2010, 00:30
xtrattitude4u wrote:Ive been told by several people that the rear O2 sensor is only for monitoring that the catalytic converter is functioning properly, and doesn't affect fuel trim. The ECU may only check this sensor periodically.
by t5ftw » 08 Oct 2010, 00:32
ziggy55 wrote:Can you please provide me the link for the TSB. This issue is driving me nuts. I have replaced both sensors and tried a another ECU, rear sensor still always reads 0V in ECU. I scanned an identical car and getting readings from the rear sensor.
by chernobyl1 » 02 Apr 2011, 14:42