When I replaced the starter on my '05 F150 w/5.4 I removed and reinstalled the air cleaner. Now I have the emissions engine symbol lit on the dash. I've done a cold start and mixed driving at least 4 times and it still hasn't gone out. The truck is running great with no problems. Any how long it will take for the symbol to go out?

 

Check that a wire on the MAF (Mass Air Flow) sensor did not break, or that it's connection is loose. It's the only sensor I can think of that may cause the emissions symbol to light up. Also check that there are no loose clamps or split elbow connections, allowing unmetered air to be getting past the MAF.
Perhaps you also broke wiring by the O2 sensors while working on the starter.


Take it to an automotive parts store, and have them check for any possible stored codes; most will do this for free.

 

I apologize I meant I replaced the alternator.

 

what brand alt did you install ?

 

I had an emergency (had to leave due to a death in the family) and had to buy a reman from carquest. It clearly resolved my problem. We're currently 13 hours from home and don't want to try anything new since it's running great. We're headed home Saturday. Once home I'll get the scanner out and see what I can come up with.

 

It took a week but it finally went away. It took 4 long cold starts with mixed driving.
Thanks!

 

Glad to hear it, just in case, I would keep checking it with a multimeter every so often or have one of the local autoparts stores do their free test.