Ford Contour

PREMSBERG

MEMBER
FORD CONTOUR

I have a 1997 ford contour 2.0 liter 4 cylinder 169,000 miles. I just had to have the water pump replaced at which time they also replaced the timing belt, accessory belt, changed the oil and oil filter. I have a check engine light on code says po171 too lean bank 1 that's been on for a while. Before the work was done, car idled fine, never stalled at lights, etc. Immediately after I picked up the car, started to idle very low (500), rough, died at lights, etc. Took it back, was told it wasn't anything they did, told me I needed to change my O2 sensors and basically treated me like a stupid woman and sent me on my way. Can you help? I need to fix this the most inexpensive way possible. Thanks so much.
Pam

1 Reply

SERVICE WRITER

MECHANIC
9,123 POSTS

Hi Pam,
Should we go down thier and kick thier. :Lol:

It may or may not be related to their work. It needs to be diagnosed and then a determination may be able to be made. Po 171 has many possible causes.

Here are some possibilities for the code:

Air Measurement System
MAF sensor (contaminated, damaged, malfunctioning, etc.)
Fuel System
Fuel pressure regulator (leaking, malfunctioning, etc.).
Fuel filter plugged, dirty.
Fuel pump (weak, check valve leaking, etc.).
Leaking/contaminated fuel injectors.
Low fuel pressure or running out of fuel.
EVAP canister purge valve leaking (when canister is "clean").
Fuel supply line restricted.
Fuel rail pressure sensor (incorrect reading).
Air Induction System
Air leaks after the MAF.
Vacuum Leaks.
PCV system (leak, valve stuck open, etc.)
Improperly seated engine oil dipstick.
Exhaust System
Exhaust leaks before or near the HO2Ss (exhaust manifold gasket, mating gaskets, etc.).
EGR System
EGR valve tube/gasket leak
EVR solenoid vacuum leak
Secondary Air Injection
Damaged/malfunctioning secondary air injection system (mechanically stuck valve).

I would check to make sure the air snokel is on tight. If so, would try cleaning the MAF sensor. On the contours, there is a vacuum tube that can crack that attaches to the brake booster. It's hard to find without a smoke machine however. Also as good maintenance I would do an air induction service. I like to use castle hydroblast. You spray it into a vacuum line such as the brake booster line if nothing else is accessible. Full spray for 3 minutes, stall the engine with it or have someone kill it while your spraying. Let it set for a few hours then take for a short drive in low gear, revving the rpms to help break it up. First use Castle cleansrite to clean the throttle bore. Try to get the throttle plates scrubbed good with a brush, while your spraying. Use a rag to wipe the carbon out between brushings. Seafoam is another good product, but smokes a lot.

Don't do anything for a day or so to see if you get other answers from some of the techs, they may point you into a better direction, as we are on the net :wink: