Will replacing the O2 sensor improve the fuel mileage of my 1993 945T? It currently gets 22-23mpg (US). The CEL is not on. I just replaced the O2 sensor on my 960 and was able to improve the gas mileage. The OBDII didn't flag it as faulty, but nothing else was able to increase the 960 above 24mpg.
Marlin

Dear Marlin,

May this find you well. How many miles on the car, or - if the sensor has been replaced - on the sensor? After 100K, you're on sound ground if you replace the sensor. They often fail gradually. See the FAQs for the test method.

Hope this helps.

Yours faithfully,

Jay E.

The car has 173,000 miles on it. I've had it since 88,000 and I've not installed a new one. It appears that on my 960 the sensor had degraded somewhat, but not enough to trigger the CEL. 23mpg seems to be about average mileage for 940T's, from what I read. But after the increase in mileage on the 960, I thought I'd see if anyone had experienced an increase after changing the O2 sensor. Thanks.
Marlin

The car has 173,000 miles on it. I've had it since 88,000 and I've not installed a new one. It appears that on my 960 the sensor had degraded somewhat, but not enough to trigger the CEL. 23mpg seems to be about average mileage for 940T's, from what I read. But after the increase in mileage on the 960, I thought I'd see if anyone had experienced an increase after changing the O2 sensor. Thanks.
Marlin