1991 940 2.3 Estate, Part Number Needed. Very High MPG!!!!

[jonesg]

Did you forget to check the fuel pressure regulator?
Its at the front end of the fuel rail, pull the vac line and check for fuel.
If its dry then I'd look at the O2 sensor, if that is bad it will send incorrect mixture signals to the computer.
Its common for sensors to go in bunches, one goes south and ruins the next.

Coolant temp sensor made your engine too rich, that can affect the O2 sensor as the computer tries to compensate but eventually the O2 sensor dies. The O2 sensor can trigger those codes too.

Read the faq,
http://www.brickboard.com/FAQ/700-900/E ... iagnostics

[squealey]

Did you forget to check the fuel pressure regulator?
Its at the front end of the fuel rail, pull the vac line and check for fuel.
If its dry then I'd look at the O2 sensor, if that is bad it will send incorrect mixture signals to the computer.
Its common for sensors to go in bunches, one goes south and ruins the next.

Coolant temp sensor made your engine too rich, that can affect the O2 sensor as the computer tries to compensate but eventually the O2 sensor dies. The O2 sensor can trigger those codes too.

Read the faq,
http://www.brickboard.com/FAQ/700-900/E ... iagnostics

Is the O2 sensor also known as the Lambda Sensor? I replaced this with a Unipart universal sensor last December when I replaced the cat. Do you think it could have gone already?

I checked the fuel pressure regulator, I have taken the pipe off it whilst the car is running and there is no fuel leakage, the car just idles a little faster.

Cheers

Wayne

[jonesg]

I'd assume the O2 lambda is ok if new but it can be tested.

Higher idle with FPR disconnected is normal, you're sucking air into the intake, making it leaner.

Its possible the plug on the coolant temp sensor is dirty, if you can...try unplugging and re-plugging it back, its a bit of a reach getting a hand up there.

[navyblue0937]

Try to check the O2 lambda and cooler temp sensor if its working, unplug it and replug it back, clean it up, and try try to start it up to see if it's working.

[sony2000]

Will a code show a faulty detonation sensor?

[jonesg]

Will a code show a faulty detonation sensor?

yep, 143. Print codes out and keep in the haynes manual.

http://www.brickboard.com/FAQ/700-900/E ... DCodes.htm