I have had 16-17 mpg when the car was dead stock city driving when the car had about 65k miles on it now its close to 90k and it has longtubes true duals and ram air, also just replaced opti. Now I get maybe 14 mpg if that, usually like 190-210 miles per tank when I used to crack off 250-260 miles. Im curious if the o2's could be inaccurate in thier age or something or if they are either good or bad and no where in between? Or if there is anything else I could check that could effect gas milage and have gone fowl at 90k miles?

 

Basically, that is what happens to them. They get contaminated over time and mileage may slowly suffer, because they cannot sense changes as well.

 

Thank you for the immediate response lol, I think Ill try to find some delco replacements and see what it does. Is there a best place to get these or would jason be my best bet?

 

You won't find them much or any cheaper than Dal or Jason.