GM Repair Questions? Ask a Mechanic for Answers ASAP
Great, I will go do that right now and then email you back!
I went to my local advanced auto store and I got 4 codes (listed below). Ironically once the error codes were cleared the problem went away. I know that they will be back, because they always come back. When the problem started about 18 months ago I took it to the dealer and they told me that is was the intake gasket before they even ran the codes on it. Ironically they also diagnosed the SES light when the vehicle was 6 months old as a loose gas cap. In the last 18 months I have been able to turn the truck off and restart it or reclose the gas cap to stop the SES from showing up. In early October this 2 day problem started suddenly and ended just as suddenly. My typical fixes did not reslove the problem, it just went away on it's own. On Sunday afternoon the promblem reoccured and did not resolve it's self until I drove it to Advanced Auto tonight. It happens on the cold start, while it warmed up, occassionaly when I turn the car off it smells like rotten eggs - like it is running to rich. I don't beleive it is the intake gasket because the problem is intermitant. Once I reach speeds of 25 - 75 the problem does not affect the preformance of the vehicle, only when I slow for a stop sign, light etc.
P0171 System Too Lean Bank 1
P0300 Random/multiple cyc misfire detected
P0131 02 sensor circuit low volts bank 1 sensor 1
P0300 Random misfire cyc misfie detected
Sorry for the delayed reply, I was out of town for the day.
Lindon J Dewey
Ok, I have a couple of bulletins for you to check out.
This PI was superseded to update parts information. Please discard PIP3232A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
99 through 05 GEN III truck engines may experience any of the following:
The intake gasket seals may be leaking around the intake ports, causing a lean condition. The intake gasket seals may leak around the bottom side of the port, making it a challenge to detect the vacuum leak. The technician may also notice lower than normal MAF readings if the intake seals are leaking.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
Some customers may comment on a Malfunction Indicator Lamp (MIL) On or that the MIL is flashing. An actual engine misfire may or may not be felt along with an incorrect idle speed. Typically this occurs during cold winter months, on cold engine starts. Some vehicles may have been previously serviced for the same condition. Technicians may also find the following DTCs stored with the Tech 2® P0131, P0133, P0134, P0137, P0138, P0140, P0151, P0153, P0154, P0157, P1133, which may be in conjunction with P0171, P0174, P0300 and P1138.
Water shock occurs when water droplets are present in the exhaust. The water in the exhaust contacts the sensor element inside the HO2 sensor, causing the HO2 sensor element to crack.
Upon diagnostic investigation, the technician may find that the HO2 sensor requires replacement. In addition to replacing the affected HO2 sensor, these vehicles should also be reflashed with the latest PCM calibration. An updated PCM calibration will be available to dealerships as part of TIS 2000 incremental satellite update 11.0 (NAO version 25.010) or greater. Always, make sure your Tech 2 is updated with the latest software version.
Important: If a DTC P0420 or P0430 is stored along with DTC(s) P0300, the catalytic converter diagnostics in Service Information (SI) must be followed to determine if the catalytic converters are operating properly.
I took the truck to Advanaced Auto had the codes read. Once that was done my husband went a bought an O2 sensor and replaced that. Thank you for your reply, it is exactly what my husband thought it was, your answer confirms that our dealer should have given us better advice. By paying you and buying the 02 Sensor I think we saved an unneccessary repair bill.