1998 Ford Contour Misfire and car running Lean

Tiny
GREGGROBINSON_111
  • MEMBER
  • 1998 FORD CONTOUR
  • 4 CYL
  • FWD
  • MANUAL
  • 159,000 MILES
Hello, my car has a misfire on cylinder #3 as per my ob2 reader. I have talked to a few people and they told me to replace the wires and plugs which I have done. The car only misfires under a heavy load when you want to accelerate really quickly. Also I just had a code come up "P1131 HO2S 11 Indicates Lean". Does this have anything to do with my problem and what are the procedures to fix the misfire. Thank you. Greg Robinson from Windsor, Ontario, Canada.
Tuesday, May 13th, 2008 AT 3:36 PM

1 Reply

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Check the no.3 compression and injector if its a MPFI type.

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)
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Tuesday, May 13th, 2008 AT 3:46 PM

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