1) If all of the emissions will be turned off in the computer, Will gas mileage decrease??

2) If I use cats and o2 sensors (without programming PCM to cancel emissions) will o2 sensors burn with a little big camshaft (240/246) and long tube headers??
I hope you understand what I mean (sorry for bad sentence)

2 important quesitons for me all replies will be read carefully

 

woww really?? 45 views, but no answer

 

The biggest influences on fuel mileage are driving style, a good tune-up (properly functioning wires, plugs, O2 sensors, air filter, fuel filter) and proper computer programming. The emissions systems (EGR, smog pump, PCV) deal more with pollution than fuel mileage. It's also true that the emissions systems don't rob any power and are better off being left in place.

 

And for the second question?

If I use o2 sensors with my long tubes and kindly big cam, cats can't do their job good and o2s will be plugged and SES light will appear right??

So the only way to solve this, is cheating by using o2 simulators or program the PCM, is that true?

 

You can't use "sims" in the pre-cat postions. You either need to run the sensors, or you need to have the PCM programmed to run in open loop. Sims are for the post-cat sensors, and since you've never told us the year of your car, we don't even know if you have post-cat sensors.

 

sorry My car is 97 and I have 4 o2s