O2 sensor and gas mileage

Replaced MAF sensor last week and check engine light went off.

Still the the upstream O2 sensor is bad reading at 00.00

Will this effect gas mileage?

My truck is a Toyota Tacoma 2002

What kind of gas mileage can I expect from this truck?

From a full tank to empty? Would think around 320 miles to a tank and would be happy.

Anyone?

Stan

 

What engine, transmission, tire size, geography, driving style, commute type, etc do you have?

 

The first sensor your A/F sensor. It is what the ECU uses in it’s process to get the best mpg and power possible, and to get the A/F ratio as close to 14.7 as possible. If it isn’t working, the engine is going to go into a pre-set fuel map that will be extremely rich. You’ll have no power or mpg

 

Have a V6 3.4

And currently, getting around 122 miles on a half tank, So 244 miles to a tank ?? That's a bit low. 13 miles to a gallon and i'm very easy on the gas.

I also have a 2006 Toyota 4 runner V6 and I get 338 miles to a tank so something is not right with my Tacoma.

 

So now put O2 upstream sensor in and check engine light came back on....going to auto parts store to read code.