Check Engine Light With Code P0171 and/or P0174 on Buick Regal

The exhaust gas recirculation (EGR) tube which connects the EGR valve to the intake manifold may develop an engine vacuum leak, causing the Check Engine Light to illuminate with code P0171 and/or P0174 stored.

RepairPal Verified
Average mileage: 125,000 (100,000–150,000)
Exhaust & Emissions affected: 3.8L V6
8 model years affected: 1997, 1998, 1999, 2000, more2001, 2002, 2003, 2004
14 people reported this problem
1 person shared problem details
Related Items:
What keeps causing my MAF to fail or trip the check engine light? I have replaced it 2 times in...
The coolant level drops slowly, but no coolant appears on the ground beneath the car. Radiator...
The "ENGINE" light has been on for a year .... after THREE diagnostic tests, the best the so-ca...
...) may become demagnetized and/or fall off of the camshaft gear causing the Check Engine Light (Service Engine Soon) light to illuminate. On higher mileage vehicles it would be advisable to replace the timing...
My brake lights dont work unless my high beams are on and i have checked into this issue and no...

Related Content