Skippy, you may very well have long-term (minor) damage already. Never run less than 91 octane in a bone-stock L67.

Back on topic folks. The topic author doesn't have an L67.

John... pm oldsman105 and see if he'* got a scantool for your year. IIRC he does and could view the O2 sensor and see if it'* getting slow or old. The o2 is pretty common for this type of fuel mileage dropoff..but we'd rather ensure it'* the right part to change out.

No questions are viewed as rookie questions, afterall.. no one was born knowing all this stuff. Ask away.. you may get tons of views due to the member size of the club.

now i'm looking for "Buickman IIRC" tried search but couldn't find anything.
Found Oldsman but he is not answering

buickman104

http://www.bonnevilleclub.com/forum/...profile&u=5578

I will second what has been said - Do the easy stuff now. Fukk tune up (Oil, filter, air filter, PCV valve, Plugs and wires). And stop wasting your money on premium gas. Just use good old regular. Our SE'* were made for regular (The supercharged folks tend to forget about us at times ), and it burns easier, so you'll get at least a little better MPG

Thanks a lot everybody

Switching to Regular on the next full tank + will put some injection cleaner in it.
Will see if i can get Scan tool and if it helps.

Thank You all Again.

Truly Yours,
JD

I got the PM. I will help this member get to the bottom of this

Got to the bottom of it! It turned out that his O2 sensor was shot and the wires were shot aswell, the plugs were worn, the air filter was pretty dirty, and used MAF sensor cleaner to clean his MAF (it was pretty dirty too). So we did a tune up and his fuel economy has improved as well as the cars peppiness. We did notice that both his valve cover gasketts are leaky. So he will get that fixed a little later when more fund$ are available!

Wow! you guys are very nice to help him out.
I wish I could get that kind of assistance. I have a feeling I am in the same spot as he is (was) in