Iam getting ausedO2 sensors from eBay very soon,front and rear.
Recently i got trouble code which is A24-3-5
The question is should i replace both sensors, or just the front one.
and i was wondering how bad is driving with broken o2 sensor, I have never taken it outon a long distance drive thoughbecause of gas mileage but I’ve been driving it around camp for a while.
Thank you!

 

Some say retiring O2 sensors affect your gas mileage noticeably, while on some cars this does not apply. My '88 Accord ran fine with the O2 sensor disconnected. However, many 850 drivers have reported that those O2 sensors (two on turbo, one on NA) do affect fuel consumption quite a bit.

If one sensor is retiring, the other is pretty much in the same condition. If it were my car, I would do both. And I would do them with direct-fit OEM Bosch sensors and would avoid universal-type sensors. Also note, that vacuum leak seems to trigger O2 sensor code so make sure there is no vacuum leak.

Other members will be replying shortly.


JPN

 

I cannot argue with JPN's advice and logic. If you can afford it, replace both, and please use the direct fit OEM sensors as Volvo's seem to be finicky about using aftermarket branded ones.

 

you right, the gas mileage went down to 10 miles per gallon but i just got parts today so i'll try to replace it to the end of the day and see what it does.