1999 Other Ford Models Oxygen Sensors

1999 FORD
130,000 MILES • 4 CYL • FWD • MANUAL
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KIMBERLYCOY
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I ran a diagnostic check on my car because the service engine light keeps coming on. I got the code p 1131 and looked it up online. I found that it was the O2 sensor. I called a parts store to price it and was told there are 2 on the car I have and my question is, which one of the 2 is it more common to go out. It is an Escort ZX2.

Thank you.
Apr 8, 2009 at 7:20 PM
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MHPAUTOS
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Hi there,

with 2 O2 sensors, the up stream sensor is the active unit, the down stream is for collaboration, you can check this by, clearing the codes and un plugging the rear sensor, and see if it set the same code.

Mark (mhpautos)
Apr 8, 2009 at 8:21 PM