You need to list all mods when you ask questions like that.
Are injectors properly scaled? Who tuned the car?
It can be a faulty front O2 sensor, which will lead to maxed out fuel trims and possibly rich misfire as someone mentioned.

Depending on mods your plug heat range and gap may be wrong (too warm and too wide) and this may cause a misfire as well.

 

fp green pte 680cc injectors,megan manifold,megan 02,ngk 7 heat range 2 dollar plugs gapped at .26 .i already replaced both fron and rear 02sensors,car was flashed by the shop and the injectors were scaled

 

some people say it can be the fpr,bad injector,or bad cas

 

Im having the same issue.. I got code PO172 and PO300, it sputters at 5k also.. Started happening after i had my clutch installed.. One thing for me is that my fp whines VERY loudly.. Ill have to do a fuel pressure test, or boost leak etc...

 

You may have a boost leak. Check that.

 

evil evo are you getting bas gad mileage?

 

yes..Ill be bringing the car to TTP-E soon when i have free time. Once they figure out the issue, i will keep you guys informed

 

ok keep me posted tomm im bring my car to my friends shop i dont think i have a bad fuel pump i upgraded to a 255 walbro last year but who know i just wanna get a fuel pressure test

 

i dont think its a bad cam sensor

 

mine does the same but i swear it was bad gas..everytime i put in better gas it starts running good again..

 

i dont think its bad gas maybe a bad fpr,fuel pump.or injector

 

After a battery change? That could be the problem. If something arced or grounded it may affect the tune.

 

Keep me posted!



battery change wouldnt have anything to do with the car sputtering.. Im leaning towards a bad fuel pump in mine or a bad front o2 sensor..We'll see

 

Take the car back to the shop.

 

it may be a fp well know tomm