Will changing the O2 sensor change my MPG?

[cb7sk8rdude]

I saw that changing the O2 sensor could change your gas mileage. To my knowleadge the Oxygen Sensor tells the ecu how much gas to give the engine. I currently get around 24 Mpg in the summer and 20 in the winter. I think I drive pretty lightly on the gas pedal. Would changing the sensor make my gas mileage better?

I have an automatic f22a1, slightly wider tires, and a short ram intake.
Thanks!

Edit: the previous owner said he never changed it. The car has 159k miles.

[Gotz Cb7]

Well, it's a possibility. Although your o2 sensor may be working, it may also be very old. If you were going to replace it, make sure you get an OEM one (Denso). Stay away from Bosche. For some reason, our cars don't read them. It'll throw a CEL after a little while. I was a victim of this because I went cheap! Going cheap isn't always the best. carpartswholesale.com has Denso's for about 80 bucks. (at least 2 years ago they did)

Some people don't have issues with Bosche, but our cars also have a hard time throwing an o2 sensor code. I didn't have an o2 sensor on my car for a month, and it finally threw the code 2 weeks later.

[cb7sk8rdude]

Well, it's a possibility. Although your o2 sensor may be working, it may also be very old. If you were going to replace it, make sure you get an OEM one (Denso). Stay away from Bosche. For some reason, our cars don't read them. It'll throw a CEL after a little while. I was a victim of this because I went cheap! Going cheap isn't always the best. carpartswholesale.com has Denso's for about 80 bucks. (at least 2 years ago they did)

Some people don't have issues with Bosche, but our cars also have a hard time throwing an o2 sensor code. I didn't have an o2 sensor on my car for a month, and it finally threw the code 2 weeks later.

Did your MPG change when changed your sensor?

[mtnbikaah]

Going cheap isn't always the best. carpartswholesale.com has Denso's for about 80 bucks. (at least 2 years ago they did)

Some people don't have issues with Bosche, but our cars also have a hard time throwing an o2 sensor code. I didn't have an o2 sensor on my car for a month, and it finally threw the code 2 weeks later.

Denso's at rockauto.com are between 30-40$

[illinois_erik]

Anyway to clean them w/o damaging them. I got one that looks good off another car with maybe 90k miles. The wires and boot over the wires looks new, just the tip is really carbonated

[deevergote]

Carbonated

I've always wondered if cleaning was possible... I'm sure it is. Still, with quality replacements being so cheap, new is ALWAYS better.

If your o2 sensor is functioning properly, a new one won't do anything different. However, a 20 year old sensor may not be functioning perfectly... and a new one certainly wouldn't hurt.

[Gotz Cb7]

Did your MPG change when changed your sensor?

With the new sensor I was getting an average of 35mpg hwy, with a short-ram intake as the only modification. It was a SE Automatic, f22a6. I measured this by driving to Va Beach, filling before I left. When I got there, I refilled and it took 10.2 gallons. I'm really not sure what it was getting with the factory o2 sensor (that was in since 1991), cause my dad owned the car before me. When I bought it off him, 2 days later the CEL came on for the o2. He was getting alright mileage. From his home to mine it was 280 miles. Filled the car before he brought it to me. I filled it back up right when I got it legal and it took 12 gallons. That's about 23mpg. So it seems like it did better. But also, the o2 could've went bad way before all of that since our cars don't like to throw the o2 sensor code. For the price of a new o2, it would definitely be worth it.

These cars are capable of some very great gas mileage. A lot better than this ecotec/hybrid junk. Cars these days that have good gas mileage lack every bit of power. These cb's have the power when you need it while gettin' 30mpg+, easy. A Cobalt driving it like a grandma, you'll see mid 20's. They say 36mpg, but they may not even get that with it on jack stands.

[Bad_dude]

Well, my car is a 90 LX Auto and it's getting highest 26, but mostly 23. I think I am going to change the O2 sensor next month to see if it gets better gas mileage.

[XtC-604]

Yes, if your sensor is old/broken.
I noticed that my fuel consumption went from 14.6L/100km to ~12L/100km when i changed my 02 sensor on my S

[jst_4_kiks]

There is a way to clean the o2 sensor. I have had them work better for about 4 months or so after doing so.

The way I do is as follows. (If you don't feel safe doing so, don't do it. I'm not resposible for what you do to your car or how you work on it)

1) remove sensor from manifold or pipe (depending on where your is mounted) and unplug from car.
2) use a wire wheel (perferably on a bench grinder for better control. Can be done with a wire wheel on a hand held tool) to clean off the sensor tip (part that's inside exhaust)
3) blow off sensor end with compressed air
4) spray sensor end with brake cleaner until it is dripping off.
5) light end of sensor on fire with lighter or small torch. This will make dropping fire balls on to ground or floor. BE CAREFUL!!! This will burn off all the brake cleaner that you sprayed.
6) repeat steps 4 and 5 three more times.
7) put a small amount of antiseize compound on sensor threads only and reinstall into exhaust.
8) reconnect wiring harness for sensor
9) disconnect battery and reconnect after 15 minutes.
10) drive car normally for 50 miles or so to have ecu relearn o2 sensor function.

95% of the time this way works for me to have no issues with a bad or slow working o2 sensor

[Bad_dude]

There is a way to clean the o2 sensor. I have had them work better for about 4 months or so after doing so.

The way I do is as follows. (If you don't feel safe doing so, don't do it. I'm not resposible for what you do to your car or how you work on it)

1) remove sensor from manifold or pipe (depending on where your is mounted) and unplug from car.
2) use a wire wheel (perferably on a bench grinder for better control. Can be done with a wire wheel on a hand held tool) to clean off the sensor tip (part that's inside exhaust)
3) blow off sensor end with compressed air
4) spray sensor end with brake cleaner until it is dripping off.
5) light end of sensor on fire with lighter or small torch. This will make dropping fire balls on to ground or floor. BE CAREFUL!!! This will burn off all the brake cleaner that you sprayed.
6) repeat steps 4 and 5 three more times.
7) put a small amount of antiseize compound on sensor threads only and reinstall into exhaust.
8) reconnect wiring harness for sensor
9) disconnect battery and reconnect after 15 minutes.
10) drive car normally for 50 miles or so to have ecu relearn o2 sensor function.

95% of the time this way works for me to have no issues with a bad or slow working o2 sensor

It sounds like good method there. But a new Denso from RockAuto is only $29 shipped. Would you risk cleaning then not working or burn yourself from brake cleaner flame?
I might be looking at that since I am unemployed.

[jst_4_kiks]

It sounds like good method there. But a new Denso from RockAuto is only $29 shipped. Would you risk cleaning then not working or burn yourself from brake cleaner flame?
I might be looking at that since I am unemployed.

Just need to get the sensor to read correctly for a month or so so the check engine light dosnt come on to pass emissions for state inspection. Tell the customer that I can try cleaning it and they come back in a few days to be retested to see if they passed. Eventually they buy a new sensor because the light comes back on and the car won't pass inspection again or they get bad mileage.