My 03 F150 4.2 is setting the 171/174 codes. This is a lean run condition. I have cleaned and checked the IAC and throttle body, sprayed either all on the vacume hoses and intake, and "nothing". Anybody got any Ideas as to what I need to check now. It only has 163k mi. and runs like a top but keeps setting the codes ???

 

Most common question on the net as far as DTC's. Google is your best fiend most definitely, since there is countless reasons why you may be getting those DTC's stored in the KAM.

 

OK, what is a DTC and a KAM ? I have no idea what you are saying here! I only speak "hillbilly"..

 

Diagnostic Trouble Code and Keep Alive Memory yall.

 

I'll get my Grandson to look that up, I'm on a "dialup" and it takes about 2.5 days to get anythig to download.. I guess that I'm so "OLD school" that I still love flatheads, and carburators... But I love this F150, just don't like seeing codes all the time..

 

I'd start at the air box and work from the MAF O-ring back.