Hi,
I was reading and some people were saying that replacing the O2 sensors will yield better gas mileage. Seeing as mine have never been replaced and I have 161K miles, would it be a good idea to replace them?

 

When Should You Replace an Oxygen Sensor?

 

short answer is maybe. If they need replaced it will yield better mileage. if they don't it wont. I'm about to do mine but that's because im putting headers and a high flow cat on my car. Yours MAY need it, but i cant tell you that for sure. The either way new parts cant hurt... but they are not cheap, even the ones Craby (the all knowing entity you will surely meet) said don't use run 60+ and there are 3 of them...

 

Use a scanner to look at the sensor activity, it should be switching from high to low voltage and back at a rapid pace. A sensor that switches slowly or stays at one value is a lazy sensor and will give poor mileage. This only applies to upstream sensors (before the cat). OBDII cars will set codes when sensor activity is low.

 

What kind of scanner? Could I just use a multimeter to see what the voltage is?

 

OBDII scanner, not a plain code reader. There are many different brands, the more features the higher the cost. You may be able to get the car scanned free at a auto parts store.

 

Oh ok cool I guess I'll try going to an auto parts store and see if I can get it scanned. Thanks for the help!