Check engine light on with 2 codes p0171,p0102 ??

[njl4]

Just pulled the codes from my 99 contour 4 cyl 2.0 143,000 miles on it. the codes are as followed P0171 and P0102 what are these codes telling me, is it the mass air flow sensor??. I just replaced the fuel filter, all 4 injectors, O2 sensor and all the plugs which look fine in color. Compression is fine in all Cylinders. I'm at the point where I guess I need help with this, all help with this problem will bee greatly appreciated.


Thanks, njl4

[G O R T]

P0102 Mass Air Flow circuit Low Input.

P0171 System Too Lean - Bank No. 1.

Make sure the MAF connector is clean and free of corrosion.
Try cleaning the MAF element with contact cleaner.
Make sure there are no intake leaks between the throttle plates and the MAF.

[MrKBStewart]

This is not for those with a vacuum leak. This is for those with no vacuum leak no maf problem no egr system issue. Ford built a few vehicles with a vacuum line that goes to the brake booster that is also teed with a line that goes to the intake tube in front of the throttle body. Vacuun must dead end to create vacuum. With a constant source of air as is supplied by the line going to the intake tube the iac and maf never get a good reading and cause idle issues performance issues as well as the system too lean code.Ford swears they never designed a system like this but I have seen it more than once. If you remove the line between the tee and the intake tube your problem will go away. ( be sure to cap the now unused ports!) Vehicles that I have seen this in include Explorers, Contours, Mystiques, Escorts and ZX2.