CODE 0171

2003 Mitsubishi Outlander • 120,000 miles

Check engine light on then off for past 3 years, I put fuel injector cleaner to pass inspection, rough idle, problem starting after adding gasoline at times, cleaned fuel injectors at Jiffy Lube, replaced oxygen sensor before catalytic, new fuel pump /filter, cleaned throttle body, EGR, tune-up done, new PCV, Checked vacuum leak negative, Dealer cannot fix problem, says leak could be coming from firewall. CARMD states I need to replace wiring harness where O2 sensor was replaced?
If you can solve this mystery I will gladly pay you for your advice. Moreover, you would be the only person to solve this matter


The first thing I need from you is the exact code number you have in the computer not code descriptions?

Jun 10, 2013.
Enclosed are the test they ran on said vehicle.

The initial code is P0171 left bank lean

So is the P0171 the only code you have currently?If so they have to check for a vacuum leak. That's where I would start. Has any one ever done a smoke test on it where they pump smoke into the intake to look for vacuum leaks?

Jun 10, 2013.