Replaced Oxygen Sensors and MPG Suffered

This is a good idea. I have installed them but I might try flushing them with air...I'll post result of gas mileage shortly, taking a trip soon so I should use a couple tanks to measure.

 

Since the replaced O2 sensors I have gotten increased gas mileage. My mileage is now around 22 mpg, so I have to say the 02 sensors helped...but not to the original gas mileage. There is another factor that I didn't even think about and I think may be the reason of some of the gas mileage drop... About the same time I replaced the sensors I also fixed the AC. I am kicking myself for not remembering this...but 3mpg is still steep for some AC.

This leads to another question...using the old 02 sensors has gotten me 2 mpg. Should I use them or in fear of cutting my engines life short, use the new ones.

 

I would run your originals, the ones with better mileage, as long as they aren’t throwing codes, or get higher quality ones.

What did you do to fix the a/c? If you have a bearing ir something going bad in the compressor, I would imagine that could account for a mileage drop.

 

the A/C will introduce drag on the system cutting your mpg.

using the old sensors could potentially cause more problems

 

I installed a brand new compressor

 

Takes energy to spin an AC compressor, new or old. I don't use min much, so my MPG (ave. under 20 combined) is without the AC. Wish it was higher.

 

Remember that the defrost engages the ac compressor. I only use the defrost when absolutely necessary. I see a 2 or 3 MPG decrease when using the defrost heavily.

 

I am actually trying to figure out how to toggle the AC when using defrost. I have another thread going about that.

https://www.tacomaworld.com/threads...turn-on-my-heater.516031/page-2#post-16366026