I just changed the spark plugs in my 2006 5.4L.A mechanic hooked his scan tool to my trucks computer before i changed the plugs.He told me that because my plugs were in such bad shape,the computer adjusted the fuel really rich.He said i should have the fuel trim put back to normal after i change the plugs.He said it takes the computer so long to lean the fuel back out,that it will end up with gas in the oil and that might wash out the bearings and cause major damage.Has anyone ever heard of such a thing?The truck runs absolutley perfect,doesn't smoke.

 

Ok........
Disconnect the battery cable for 30 minutes, this wipes out the ECM's memory and it's just like firing up the engine for the 1st time.

IMHO...I think the mechanic is smoking something!

 

Yea i thought it was strange to.What you said makes sense,i had the battery disconnected over night and for half the day while i was changing the plugs.And like i said it runs perfect.I thought i would ask just in case there was truth to what he said.Thanks!!

 

Well...I just talked to him,he said the computer is what's called an obd2 system.He claims it can't be reset by disconnecting the battery.I don't know what to think about this???

 

All ecm's including obdII, loose their memory when the battery terminals are disconnected ...it takes between 10 - 30 minutes............he is smoking something funny IMHO.

 

The mechanic is either an idiot or is clueless. Find a different one.

Fuel trims are stored in the PCM's Keep-Alive Memory (KAM) which resets automatically to factory defaults when the battery is disconnected, which usually only takes 5-10 minutes. Once the engine operation is restored, the PCM's adaptive learning strategy causes it to relearn the new optimal parameters for fuel mixture and transmission shifting, among other variables.

 

I see you are in Los Angeles...if on the west side, I can highly recommend Ed Little Auto Service...........family owned shop, been in business for 40+ years, same location, son has had the shop for 15 years now.....very, very honest. When I'm out of town and something goes wrong that needs attention, this is the shop my family takes the cars to.

The thing about Bob (the son) is if it is something that they can do, but the dealer can do it faster, better, etc, he will tell you that stright up. Also, if you need a dealer, I can also recommend SouthBay Ford in Hawthorne (Galpin too).....
I would avoid Airport Marina Ford/Honda like the black plague!