Ok..I took a short trip one day and maybe went 100 miles (highway) and used about a half tank of gas. Now.. I'm no rocket scientist, but that just seems to be horrible.. especially for a stock LO3 with some exhaust work done. I'm thinking it's time for the O2 sensor to be checked/most likely replaced. I ran it on a diagnostic program and was getting a ton of readings on it. The mv levels were ranging from about 30 to 1000. I heard they should be in the range of 400-800.

If anyone could help me out, I'd appriciate it.

I'm thinking I should just replace it since it is probably dead, or near it anyway.

 

i would change it if you suspect it at all, it is a cheap fix.

 

305 just get bad gas milage. I put a 355 In my camaro and it get's better gas Mialage now then when it had a 305 in it

 

a lo3 in stock form, in good tune should get 25mpg+ on the hi-way. that is not bad, IMHO.

 

well your o2 readings were good , but its probably lost a lot of frequecy. on average a new o2 will give you at least 4 mpg.just so you know o2's are almost allways bad if there even only a year or so old. o2 should sweep from 0 to 1000 at 18 to 21 thousand hertz.