I got a new o2 sensor for my NA that I plan to install. It has 128K. How much difference will a new sensor make in a car that is "natually aspirated" to get bad gas mileage and poor emissions anyway?

 

Not very important if you drive mostly city...

Somewhat important if your driving is mixed...

Very important if you drive mostly highway...

 

If you want to LOSE 20% to 30% of your gas mileage, don't bother to put it back in...


-Ted

 

If the oxygen sensor hasn't been replaced in recent history (past 30-50k miles), expect your fuel economy to jump a noticeable amount if you do any significant amount of highway driving (or even steady state city driving - anything below 3500 RPM will kick into closed loop mode if you're being light on the throttle).

-=Russ=-

 

"anything below 3500 RPM will kick into closed loop mode if you're being light on the throttle)."

You are saying it will drive my gas mileage to crap?

 

Um... closed loop mode is where the O2 sensor is used to tweak fuel delivery for optimum fuel economy.

Low throttle below 3500 RPM is a GOOD thing.

-=Russ=-

 

And, the closer you cruise to that 3500 without hitting it, the better