when mine kicked that light, i had cleaned the mass air sensor and forgot to plug up the rubber boot on the bottom of the air filter housing, where the MAS wires actually go through. plugged it back in FIXED. you might have pulled it out or it might have a hole in it. just my $.02

 

I triple checked that LOL I am a little **** when it comes to my Baby LOL I went to our shop mechanic today after work-this guy takes care of my work's vehicles and he is a FORD man! we ran the codes again and put a voltmeter on the MAF-it is out of spec! I ordered a new MAF and checked everything again just to make sure. hopfully by tomorrow morn that damn light will be gone!!

is it common for the 97-03 5.4Ls for the mass air to go bad? I have had 2 5.0 mustangs a 4.0l exploder and have NEVER had this problem. I have heard that the 4.2l f-150's do this just wondering how common of a problem this is on the 5.4Ls?

 

what did you clean the MAF with? did you touch the filament with your finger? sometimes you could get a faulty one, but they dont normally go out, at least in my experience and i've worked on fords since i was 12 and i've worked at the dealership for a long time. other than that i guess anythings possible lol

 

I cleaned the MAF w/ CRC mass airflow sensor cleaner. Completly dissassembled the MAF pulled it out of the housing. I DID NOT TOUCH THE FILLIMENT WIRES. Noticed that the vertical fillament wire was missing on the sensor so I wound up replacing the MAF sensor. My truck runs much better but the light is still on in my dash. codes P0171 AND P0174 which means a lean condtion. Triple checked EVERY dang vaccum hose on or around the throttle body. no leaks I dont have a code scanner to clear the codes. I dont want to dissconnect the battery either so the PCM has to "relearn" everything. I keep hearing bout it should shut itself off after a couple of "drive cycles?" my local Ford dealer told me this. I was thinking of changing the MAF harness that goes from the MAF to the wiring in the fender under the air box.

I know that it would be a good idea to change the 02 sensors soon anyway but $ is a little tight right now and the truck doesnt run bad. just wanna get this damn light off in the dash!

 

i wouldnt worry with changing 02s or the wiring for it unless you just absolutely want to. i guess you can drive it around to see if the light turns off. i personally dont think it will. if you do have to reset it. unhook your battery(positive AND negative), touch your terminals together for 10 seconds and hook them back up. worked for me until i got a tuner. now i'm a rolling dealership for obd2 vehicles lol. good luck

 

went back to my mechanic he cleared the codes for me!!! light is off and has stayed off YAYAYAYAYAYAYAYAYAYAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

sweet. thats good to hear. lets hope it stays off now. its a real pain in the butt having that light on all the time. now invest in a tuner and you wont have to worry with it anymore. best 200 bucks i ever spent

 

any particular brand of tuner that you reccomend?

 

i personally have a superchips 1715. i love it. i got good power and full control over my transmission. with modifications that i have and the superchips tuner, i can walk all over a 5.4l truck. that might not be your thing but i love the fact i can run with the big dogs if my "little engine that could" has too and i can still pull 6000lbs worth of trailer and car at 70 mph lol. all tuners have their pros and cons. i weighed all my options and decided superchips was the way to go. others may have better input, i'll set back and see what they have to say. good luck