P0171 code

[Henry01sport]

Hi explorer guys my name is Henry and I have a 2001 Explorer sport which I love dearly I got it for $900 and have nearly restored it. It drives like a champ and has no driving issues, but it has a P0171 code. I recently had all the vacuum leaks fixed, the MAF sensor replaced, the fuel pump and filter replaced and I had the Iac checked. I took it into the shop and they have no idea what's wrong with it. any help you guys could give would be greatly appreciated. (PS: it also idles a little low/roughly.)

 

[J_C]

P0171 is system too lean, bank 1 so you probably still have a vac leak or new vac leak. I'm wondering about the intake manifold since it's only bank 1. I'd also wonder about the O2 sensors, the upstream one on that bank.

I'd keep driving it if I really needed to, but would stop if it started getting misfire trouble codes, as unburnt fuel can damage the catalytic converter. I would still get it fixed asap, not totally ignore it.

With a scan tool (that's capable) you can look at the fuel trims to see what it's doing, but since it is rough the odds are it's maxing out the trims already.

 

[swshawaii]

BOTTOM side of the PCV elbow checked?
P0171 & P0174 4.0L SOHC's Sport/Sport Trac

Google images due to Photobucket's scam:
https://www.google.com/search?q=spo...ved=0ahUKEwi51rzIuoTVAhUK7GMKHUxUCnAQ_AUICygC

 

[J_C]

^ I was thinking not a hose or elbow because of only one bank with a code, no P0174

 

[Henry01sport]

well, before i had the vacuum leaks fixed it had very high fuel trims. but i had all of them repaired and checked again. also i cleared the code and took it on a 300 mile road trip (all freeway miles) and the light didn't come back on. but when i got back home to the city (stoplights and idling) the light came back.

 

[Henry01sport]

yes it was double checked.

 

[Henry01sport]

i just remembered i had the pcv valve replaced and the 2 days later the light came on