I have a 2004 SR5 4WD 4.0 164,000 miles. I have been having issues with P0171 and P0174 codes. I have replaced both AFRs both 02 sensors, and the MAF twice. All parts are DENSO. smoked engine
for vacuum leaks and visually inspected for exhaust
leaks.Clear code and it comes back on within 20 miles of driving. Car drives ok, although idle is low while in gear (sometimes). Also exhaust sometimes has very rich smell,
JA: Does the engine stall right after starting? And what about hesitation or jerking during acceleration?
Customer: No runs and accelerates well. Gas mileage seems to be in line
JA: What year is your 164?
Customer: ??? 2004 with 164,000 miles
JA: Are you fixing your 164 yourself? What have you tried so far?
Customer: I have done some myself and others at local shop. My original message indicates everything I have done
JA: Anything else you want the mechanic to know before I connect you?
Customer: No I think that is it