I noticed similar symptoms with my car after installing the exhaust and intake, i babied the car so the exhaust and all that breaks in but then noticed 1-2MPG lower than usually also slightly less power, so i just filled up my tank and reset the ECU before i drove off ( without removing battery terminal ) and car feels new again. it is just probably the cars learning habits or so, i definitely need a tune anyways.

 

you dont have to break in and exhaust or intake ...

 

hmmm interesting. which method did you use? the battery pull or the other? i kinda wanna just bring it into a dealership and have them do it...

 

1. Reset ECU
2. TB cleaning
3. Fuel injector service

 

Oh, and do NOT take it to dealer for the ECU reset, that's just a waste of time and money.

 

there's even a video on Youtube that shows you how to reset the ECU without a battery pull.

if you can't manage that, then please don't touch the battery, as you might get electrocuted or blow it up.

 

^ +1.

OP - do a search on this forum and you'll find lots of discussion and DIY about the easy ECU reset. it is just a exercise of pressing down the gas pedal according to a certain pattern and timing. it takes some folks a few tried to master the pattern, but anybody can do it. use a stopwatch if it makes it easier for you.

 

LOL, Let me correct that , I babied the car because referring to the exhaust since i installed it my self, i wanted to make sure no leaks, and that the Ark system was bolted on correctly, back when i had me E36 the exhaust shop welded the hanger instead of using a bushing and it popped right after slamming my foot to the pedal enjoying the new exhaust note. ever since i drive normal and to wait on the funky smell the new exhaust has.

 

Followed this video, did it on the second try lol.

 

I think you're just used to the power now... I thought the same when I first got my car. I was scared of the speed the 1st few weeks. I came from driving a F150 so it was a huge adjustment. Now I think its not as fast, then the other day I got after it on the hwy and my car was flying.

 

That also^^