WeekenderNutJob
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- Dec 27, 2022
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2008 Yukon XL Denali, 6.2L AWD - P1153 (Bank 2 Sensor 1) code even after replacing the o2 sensor.
Replaced Sensors: About a year ago I replaced both the upstream and downstream sensors on that side with AC Delco ones of the same part numbers when it had codes, which worked well for about a year. Recently started getting just an upstream sensor error, p1153, so I replaced upstream again with OEM, cleared all codes, and ECM memory reset, however, I get codes again after the drive cycle. At this point, I am not convinced it's a sensor issue anymore as the OBD Reader shows that the sensor voltage is working similarly to Bank 1 sensor 1.
Smoke Test: The next assumption was an exhaust or vacuum leak, so I smoke-tested the exhaust from the front intake and from the back exhaust for a potential manifold or vacuum leak, but I did not find anything indicating a leak anywhere on a cold engine.
TSBs: As a side note there is a TSB (https://www.tsbsearch.com/GMC/08-06-04-045A) that talks about the need to reprogram ECU due to gas sulfur levels but I assume if it was an issue with the sensor and ECU reprogramming after an o2 sensor, then it would have been an issue when I replaced the upstream originally a year ago. I always run 91+ octane gas, from top-tier stations, per the manual.
Before I take it to the dealer, for more diagnostics, or ECU reprogramming, does anyone have further suggestions on tests I can do?
Replaced Sensors: About a year ago I replaced both the upstream and downstream sensors on that side with AC Delco ones of the same part numbers when it had codes, which worked well for about a year. Recently started getting just an upstream sensor error, p1153, so I replaced upstream again with OEM, cleared all codes, and ECM memory reset, however, I get codes again after the drive cycle. At this point, I am not convinced it's a sensor issue anymore as the OBD Reader shows that the sensor voltage is working similarly to Bank 1 sensor 1.
Smoke Test: The next assumption was an exhaust or vacuum leak, so I smoke-tested the exhaust from the front intake and from the back exhaust for a potential manifold or vacuum leak, but I did not find anything indicating a leak anywhere on a cold engine.
TSBs: As a side note there is a TSB (https://www.tsbsearch.com/GMC/08-06-04-045A) that talks about the need to reprogram ECU due to gas sulfur levels but I assume if it was an issue with the sensor and ECU reprogramming after an o2 sensor, then it would have been an issue when I replaced the upstream originally a year ago. I always run 91+ octane gas, from top-tier stations, per the manual.
Before I take it to the dealer, for more diagnostics, or ECU reprogramming, does anyone have further suggestions on tests I can do?
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