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Codes P0171 and P0174

Tony Raine

Well-Known Member
Joined
August 10, 2004
Messages
153
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City, State
Bono, AR (outside Jonesboro)
Year, Model & Trim Level
'01 Sport
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
 








etinkerer1

New Member
Joined
August 17, 2008
Messages
6
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0
City, State
Rochester NY
Year, Model & Trim Level
2000 LS
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

New Member
Joined
October 29, 2008
Messages
3
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0
City, State
Milwaukee WI
Year, Model & Trim Level
99 XLS 4.0 SOHC
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.
 




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