I have just fitted a S/S exhaust to my Impreza STi. It has a de-catted down pipe and centre section with a back box. I am unsure of the make. Since the exhaust has been fitted in 3rd or 4th gear at about 3500 to 4000 RPM the car misfires. Should I put on my own sensor on to the new exhaust as the new exhaust came with a sensor or does the car have to be retuned after putting on the new exhaust?

 

Sound to me as if the sensor may be wrong, if you can, cahnge it, it's gotta be worth it just for peace of mind, and you never know, it might cure it!

 

Sound to me as if the sensor may be wrong, if you can, cahnge it, it's gotta be worth it just for peace of mind, and you never know, it might cure it!

 

Sound to me as if the sensor may be wrong, if you can, cahnge it, it's gotta be worth it just for peace of mind, and you never know, it might cure it!

 

Does it "misfire" under full acceleration?

I had the exact same issue with my fully decatted SS/MY00...it's overboost mate, and the boost cut feels exactly like a misfire in the newer scoobs.



There are ways to sort it, fiddle about with restrictors...or do as I did...get it mapped (Link).

/J