I have a '97 f250 LD with the 5.4L and had 3 codes come up. I just got this truck from a dealership about a month and a half ago. the codes are as follows:

P0135
P0174
P0171

I know what the codes are but what is the fix for them??? This is the 1st ford I've owned, since I had all chevys. any info would be great!

 

its starting to idle really rough, and it stalls once in a while. what is the reason for it?

 

Click on SEARCH and enter "P0171 P0174" as your SEARCH keyword.

Repeat for "P0135"

Steve

 

Welcome to the forum


P0171 and P0174 are usually caused by 2 things.
1) A dirty MAF. Spray electrical contact cleaner on the 2 wire filiments, but don't touch them.
2) Vacuum leak. Check the PCV hose assembly. The elbows on the ends are known to crack, especially the one the connects to the rear of the intake manifold.

P0135) The front passenger side O2 sensor has a bad heater and needs to be replaced.

Glad you're in a Ford now

 

ok I sprayed the MAF and it didnt do anything. I checked the elbows and most of the itake hoses and they were ok with a few going into the main intake boot were dry. I figured I'd have to end up replacing that stupid O2. Its nice to have a big ford like I have...tons of stuff I want to do

 

You didn't mention it, and I don't mean to be snide: but don't forget to reset the CEL after the mods -- it doesn't always go out on its own. If it re-appears after a reset, you have more troubleshooting to do...

See also this thread, running parallell to yours: https://www.ford-trucks.com/forums/s...ighlight=p0174