Wednesday, October 11, 2006

P0171 and P0174 lean mixture codes for 1999 Ford WindStar with 3.8L engine


My dash panel light is always on for about a week and when I scanned it, 2 codes showed up: P0171 lean bank 1 and p0174 lean bank 2. I replaced both oxygen sensors and cleaned the mass air flow sensor but after resetting the codes, the light is still on? All my spark plugs were just replaced including fuel filter. Help!

ATS Advisor:

Unlike GM engines where cleaning the mass air flow sensor will give you results, on Fords you have to replace it if you get this codes. However, before doing this make sure there is no vacuum leak like the PCV hoses which are prone to cracking. To be sure, have a garage to do a smoke test on your engine to eliminate the possibility of a vacuum leak.

ATS Tip:

Every time there is a lean code, don't waste your time and change the mass air flow sensor right away if there's no vacuum leak using a vacuum gage. You should get a reading not lower than 17 inch of vacuum.


Post a Comment

<< Home