cure for code

[rvhop]

Hello All, The check engine light came on in my 1996 Ford F-150. I scanned and the code was po 171 - system to lean, bank 1. What would cure this? The engine is a 5.0 liter. Thanks

 

[Birdhunter1]

Hello All, The check engine light came on in my 1996 Ford F-150. I scanned and the code was po 171 - system to lean, bank 1. What would cure this? The engine is a 5.0 liter. Thanks

Does the truck run rough at all? If it does spray WD-40 along the intake gasket surface while it is running and see if it runs better for a short time. What will happen is if it is sucking air it will draw the wd-40 into the airgap and seal it for a few seconds, long enough for you to hear it run different, then go back to sucking air.

 

[Diamondpilot]

Along this same line the last 2 vehicles I have worked on, much new than yours such as 2004's and later, but giving a similar code both had bad vacuum hose and one had a bad PCV valve hose.

It will give the same type of symptom as listed above. I found both by having someone start the trucks then shut them off quickly while I was looking under the hood. I could hear a hiss noise and tracked it down in 10 minutes.

Chris

 

[Johnp33]

Just an addition to what has been said, take a pair of pliers and clamp off the hose to the brake booster, they can leak continuously.
Also the intake gasket can pop and leak internally, to check that, remove the PCV valve and put your finger over the hole in the valve cover, if it sucks in it is manifold time.

 

[Elviscaretaker]

I'd think you'd also pull a 174 with a vacuum leak but I agree with those that say to check your PCV line. good chance you'll have a leak at the "elbow". It just might be small enough to not get the 174. Slim to no chance it's your O2. IMHO