i have no f'ing clue when it comes to engines, so i have a few questions... could someone explain what the OD button does besides make the tach jump about 1k rpms? (told you i was stupid)... and will i actually notice a performace jump by adding a few bolt on up grades like a CAI and better muffler? thanks...

i always do... i knew it stood for overdrive, just didnt know the exact mechanics of what it did..

Automatic transmission cars that don't have an OD button have it engaged already...the car shifts to fourth gear normally. When you turn the OD off on cars that have it selectable like the Celi, the tranny only shifts into 3 gears...that why when you're cruising and you turn it off the RPMs jump up...the tranny downshifted to third. >>

so how about preformance boost with adding a muffler and CAI? will i notice anything?

Just minimal...you'll feel it but it's not a huge gain. A CAI with full exhaust and muffler will make a difference...it's just not big for you to get impressed.