Question

JGUBASH1985

MEMBER
1997 FORD EXPLORER
6 CYL
FWD
AUTOMATIC
165,000 MILES

I have a 97 ford explorer and it threw the code p1131. It idles really rough at times and sometimes even kills. I can also smells unburned fuel coming out of the exhaust sometimes too. I was just wondering if you had any ideas on what it could be

Wednesday, January 19th, 2011 AT 6:01 PM

1 Reply

BLUELIGHTNIN6

MECHANIC
16,542 POSTS

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1

Any of these could be the cause of the code.

Electrical:

* Short to VPWR in the harness or HO2S
* Water in the harness connector
* Open/shorted HO2S circuit
* Corrosion or poor mating terminals and wiring
* Damaged HO2S
* Damaged PCM

Fuel System:

* Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system

Induction System:

* Air leaks after the MAF
* Vacuum Leaks

PCV system:

* Improperly seated engine oil dipstick

EGR System:

* Leaking gasket
* Stuck EGR valve
* Leaking diaphragm or EVR

Base Engine:

* Oil overfill
* Cam Timing
* Cylinder compression
* Exhaust leaks before or near the HO2S(s)
Start by checking all the parts you can visually check. More than likely it is an exhaust leak before or near the HO2S(s)