The best way to go about solving the issues is to do one truck at a time. Pick one and I will try to help you with that on then the other one. Doing two at a time is distracting.

 

Ha! Tell me about it. The 4.6 V8 is done for now. The 4.2 remains unsolved. It is running poorly at idle but great otherwise. I would have to assume IAC but Im not sure on Fords if there would be an underlying issue.

BTW I cant believe a MAF costs $200 parts only!?!?!

 

Oh and is the MAF spray cleaner any good or is it just snake oil?

 

I bought the spray and cleaned my MAF. But my question: is it necessary to take it apart (the tamper proof screws) and clean it?

Oh it didnt change anything after I cleaned it. It still dies a few times when its cold in the first few minutes of running and idles pretty rough all day.

 

IAC's were horrible for idle problems. they stick they hum holler scream growl, i think one even called me a bad name, easy way to test it, start the truck let it warm up or when ever it runs bad and tap it with a small hammer or 3/8 extension. idle canges, theres the problem. and if you popped it off, youll see all the crud built up on the pintle.

 

...and on the maf situation, spraying is not typically a good idea. the heated wire is really thin and can easily break. lessons learned during my semi skilled and apprentice days. the best way IF NEEDED is to lightly dab with a cotton swab. But unfortunatly my ration on MAFs werent great, usually they were to far gone that cleaning them only lasted a few drive cycles. the 200 bucks is a pretty fair price. steep, but not as bad as dealership. also, for the 1537 and 38, those are IMRC codes. There are two of them on the bottom of the intake. those could also be causing your lean codes(p0171 and p0174.), being stuck open most likely. I had a couple windstars that came in the shop with simular problems. I dont recall any trucks though, but the 1537/38 codes deal with the IMRC

 

Heres another good explination.


http://www.ford-trucks.com/forums/sh...6&postcount=10

if you get into it, chech the vacuum lines really good for splits.

 

Wow thanks for all your input! I will check the IAC tomorrow. Do you remember what the runners look like?

 

it could be that your cat is partialy clogged

 

I never thought about that. I wanted to lose it anyways but I wasnt sure if it would affect the O2 sensors.