Anyone-
Put an Air Raid on my 04 FX4 two weeks ago. Didn't disconnect my neg batt cable like yer suppose to do. My mpg went down to about 11.7, highway, and hopefully resetting the computer will help that. I just disconnected it for an hour and a half to allow my computer to reset. It seemed to make a diff. in idle rpm and that seems to be all it did, we'll see this weekend if it did anything for the mpg prob. My main problem is after disconnecting/reconnecting my neg. cable my check eng. light came on. Why? Can anyone tell me?

 

Something is probably disconnected. You cleared the computer, so the code has to be a new occurrence.

I would do a wiggle test on all connectors associated with the area you were working to ensure connection. If that doesn't work, have Autozone pull your code and repost.

By the way it should only take 5 minutes or less to reset with the cable off, but don't do it until you have the code pulled.

 

Make sure the MAF and IAC are sucurely connected. Sounds like you might be running in LIMP Mode.

Sidewinder

 

what's "limp" mode??

the CEL went out after about 30 miles.

 

After resetting the computer you need to let the engine idle for about 10 minutes (dont drive it).

But if you are going to reset it again, get the codes read at autozone and post it here.