I have a 01, 23500 miles full warranty till 100k. The car runs perfect at all times untill i reach about 77-8000 rpms at full throttle. it begins to backfire, mis, and hesitate badly. 1st and 2nd it is most pernounced, third takes forever to pull through the entire gear. This mainly happens when it is cold out. As far as mods go i have a test pipe, and invidia exhuast. I also took the top off my airbox. Any thoughts as to what my issue is? ANy possible fixes to try.....or should i Put the Cat back on and take it to the dealer? Thanks in advance!

 

You might want to try the famous MAP sensor whack.

http://forums.s2ki.com/forums/showthread.p...ight=map+sensor

 

Thanks ill give that a try

 

Does it always do that at high RPMs, or only sometimes?

If always, it probably won't be cured by the MAP whack (either it's caused by something else entirely, or your MAP sensor is beyond help by whacking), but try it anyways.

Having the airbox cover off isn't doing you any good, but shouldn't be causing those symptoms. I'd put the cover back on, just to help performance in stop-n-go and higher temperature conditions.

 

it does it seems liek all the time but i just noticed it this morning but everytime i took it up that high it did it after i noticed it

 

whacked the shit outa that sensor yesterday havent had a problem since!

 

 

If the situation comes back, you might consider getting a new MAP sensor. Have a read of this:
http://forums.s2ki.com/forums/showthread.p...6&highlight=map

 

Dave! Excellent info as always.