Codes P0171 and P0174

[Tony Raine]

2001 Sport, 2wd, about 95,000 miles

check engine light came on, used my buddy's code reader, and got:

P1071 System too lean (Bank 1)

P0174 System too lean (Bank 2)

I "cleared" the codes, and they came back 2 days later, so much for it being that easy, haha. This sounds like an injector problem to me. Any one out there know what they actually mean?

Thanks,
Tony



*edit--> please delete, found it in a search

 

[carlover]

More than likely its the pressure sensor for the EGR system. I has those same codes, bought a new one and it went away.

 

[etinkerer1]

Had these codes on my 2000 Explorer this summer. Struggled to get the fuel filter replaced (@#%&*# 3-prong locking clips inside coupler!). One prong was bent so the release tool wouldn't push it back far enough to release it. Had to modify the tool slightly so I could get the coupler off. Now I know you should first push in on the coupler against the filter body to relieve pressure on the clip before inserting the tool.

I also found the hoses going from the EGR valve to the sensor were rotted out on one end and had to be replaced. I had new 5/16" neoprene fuel injector hose, but didn't have any new 1/4", so I made due with a used piece. Cleared the fault and it ran a couple of months, but it came back this week. (Maybe the used piece of 1/4" hose failed again.)

Is there anything else I should check for System Lean- banks 1 and 2? Would a bad HEGO sensor cause that too?

 

[mfdbackdraft]

I too have PO171 and PO174 codes setting time after time. A KOEO test of the fuel system shows pressure builds to about 60 PSI but quickly bleeds off. WI DMV tech advisor thinks a fuel injector may be leaking.. but why the lean code instead of a rich code? The also tried cleaning off the MAF sensor with spray carb cleaner, then "tickle" the thin wire inside with the thin end of a zip tie, then more cleaner. That didn't help the codes, but as regular maintainance its a neat trick. Will check back if I find any solid leads.