Hello All,
I have been repeatedly been getting that pesky PO171 error code on my 2006 Ascender with the 4.2 engine. and around 60,000 miles. The following is what I have done so far, in order.
1. Had dealer re-flash ECM with latest version upgrades (free under open campaign).
2. Clean air box, and replace air filter.
3. Add Techron fuel injector cleaner to gas.
4. Clean MAF Sensor (with appropriate solvent) with battery disconnected for a ECM relearn.
5. Remove throttle body & thoroughly clean (with appropriate solvent).
6. Replaced the upstream Oxygen Sensor with a new AC Delco one.
7. Add 2nd Techron fuel injector cleaner to gas.
It should be noted that the truck runs & idles fine, accelerates with no hesitation, and at this point in time the only code it keeps throwing is the PO171 (after around 50 miles of driving).
I ordered a secondary air injection solenoid check valve & gasket which I heard can sometimes contribute to this error code. The valve should be here in a couple of days. Do I need to use gasket cement with the new gasket, or can I install it DRY?
Any thoughts on this situation would be greatly appreciated. I am determined to eliminate this PO171 error code without bringing my truck to a mechanic!
Thanks
I have been repeatedly been getting that pesky PO171 error code on my 2006 Ascender with the 4.2 engine. and around 60,000 miles. The following is what I have done so far, in order.
1. Had dealer re-flash ECM with latest version upgrades (free under open campaign).
2. Clean air box, and replace air filter.
3. Add Techron fuel injector cleaner to gas.
4. Clean MAF Sensor (with appropriate solvent) with battery disconnected for a ECM relearn.
5. Remove throttle body & thoroughly clean (with appropriate solvent).
6. Replaced the upstream Oxygen Sensor with a new AC Delco one.
7. Add 2nd Techron fuel injector cleaner to gas.
It should be noted that the truck runs & idles fine, accelerates with no hesitation, and at this point in time the only code it keeps throwing is the PO171 (after around 50 miles of driving).
I ordered a secondary air injection solenoid check valve & gasket which I heard can sometimes contribute to this error code. The valve should be here in a couple of days. Do I need to use gasket cement with the new gasket, or can I install it DRY?
Any thoughts on this situation would be greatly appreciated. I am determined to eliminate this PO171 error code without bringing my truck to a mechanic!
Thanks
