I have an 04 fx4 5.4 with 73,000 on it. The truck drives fine but when I have to stop my rpm's drop from 500 to 250 and back up. Then when I try to park it, it stalls on me. I just bought the truck so no idea how long this has been going on. Has this happened to anyone before?

 

do you have a programmer on it my 04 did it a few times I just had to reset the tune maybe take it to ford and have them reflash/update your ecm

 

No programmer on it but yeah I was thinking about resetting the computer. Do you think it could be the o2 censor?

 

Check for vacumme leaks.. are you getting any codes?.... Clean MAF

 

Could be the O2 sensor. Had a similar problem with a vehicle before and it was the O2 sensor.

 

Its not throwing any codes because the battery was swapped out 2 weeks ago. Im gonna try to put an idle air control valve on it and see where that gets me

 

Thats why its not idleing right and stalling.. The computer is in relearn process...Need to fill it up with gas... and pull the battery cables for for 15 mins... then plug back up... start truck with ac off... let it idle for 3 mins... then turn the ac on and let it idle for 3 mins... then turn ac off and let idle in drive with your foot on the brake for 3 mins and then idle in drive with foot on brake with ac on....

The computer will start learning the fuel trims.... give it a few weeks to start acting right... My truck takes forever to learn

 

That's what someone else told me too. I tried unplugging the leads for 20 mins, hooking em back up, turning the truck to the on position for ten mins, then starting it. Its been about 2 weeks now since I swapped the battery but I guess I need to be more patient. Ill try your trick thanks for the advice.

 

If its cold out.. my truck took 7500 miles one times... i was about to burn the damn thing

 

Should I unhook the battery everytime I try this idle thing