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.
Car Problem Reports
Chevrolet Impala Check Engine Light Due to Vacuum Leak in EGR Tube
Chevrolet Impala Problem
Exhaust & Emissions Affected: 3.8L V6
Average Mileage: 94,639 mi (16,580 mi - 162,000 mi)
Visitor, 2000 Chevrolet Impala
CHECK ENGINE LIGHT COMES ON AND OFF RANDOMLY, HAD IT CHECKED AND IT GAVE THE EGR CODE, NO PROBLEMS WITH THE CAR THOUGH LIGHT NOT ON ISSUE NOT FIXED
Visitor, 2001 Chevrolet Impala, 16,580 mi
I have changed the EGR Valve about 3 times and it's still saying The EGR Valve is open
Visitor, 2000 Chevrolet Impala, 71,254 mi
I hear air hissing when im up under the hood of the car haven't fix problem yet
Visitor, 2003 Chevrolet Impala, 122,000 mi
Check engine light came on and nothing happened for awhile. After a few months, the engine started making really loud sounds, like I was revving the engine, when my foot was not on the break or gas pedal. The noise has gotten progressively louder.
same problem. EGR valve bad. Had to replace 2 times before was fixed