I just had a diablo chip put into my 2000 Mountaineer (5.0 302 V8) along with
a new mass air flow sensor, rear gear. The problem is now it won't stay in
place when in park..it creeps forward slowly into the street..I have to
put the parking break on. Sounds like a chip problem relating to Ford's all-wheel drive? I read somewhere where some guy with a chip failure on a 97 Explorer
with all whell drive had the same problem..Can anyone help
Thanks

 

Welcome to the site..The park system in the transmission is manual and has to do with the lever as far as I know. For safety it can't be any other way. When you put it in park it better not roll or somebody broke something or messed with something..Thats my call....Its a mechanical stop.

What rear gear are U refering to?

 

Every automatic tranny on the planet (that I know of) uses a mechanical stop (so you can keep it from rolling even if it won't start). As 99f350sd said, something in the tranny itself is broken... impossible for a chip to cause this.