Originally posted by Myrosia:
I cannot find how to change the O2 sensor.

I have a 1999 Ford Contour L4-122 2.0L DOHC SFI

Also, should I have anything else tested?

Ps. That's odd - the check engine light just went off...what's that all about?

~Myrosia~




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


The O2 simply unscrews from the exhaust manifold between the engine and the radiator.

Since this engine only has one O2 for fuel metering, there is no simple way to tell if the O2 is bad or if there is another problem affecting the mixture.

Standard procedure for this code would mean cleaning the MAF, looking for vacuum leaks, and changing the O2.

The CEL will come and go as the running conditions change.

"Those who cannot remember the past are condemned to repeat it" -George Santayana