after you put aftermarket exhaust, the car is drinking gas? I feel my car is consuming so much gas..

 

how long since you put it in? your ecu needs about a week of driving to adjust to it. If it's been a long time since you put it on, you should go get a tune or at least see what your car's afr looks like throughout the rpm range.

 

I put it yesterday... I will wait for a few days then. Thanks!

 

If it's a more free flowing exhaust system, it should get better mileage, not worse. The X factor isn't the exhaust, it's your right foot. You are accelerating more aggressively than before hear the sound of the exhaust.

 

Try resetting the ECU but I think the new exotic tone coming from your exhaust is making you drive your car harder.

 

I'm not speeding at all because it loud as hell lol my car is 5AT and I used to drive with shifting but due to the loud sound now I drive with "D(drive)" lol

__________________________________________________ ________________________
'08 G37S Coupe 5AT l SPRT l PREM l NAV l Injen CAI l 245/40/19 FT/275/35/19 RR Falken FK 452's l 15% Tint l Tanabe Coilovers l MXP exhaust

 

I'll bet you are still accelerating harder than before, even if you're not speeding. It's insidious, you just can't help it.

 

I know how I am driving.. I'm 100% sure that I'm not accelerating harder than before..
I got what you mean though.. when I drove with shifting(with stock exhaust), I accelerated 5k rpm from M1 to M2, from M2 to M3 as well but now drive normally without using shift.. less accelerating... Maybe I should wait until it settled..

 

butt dyno =]

 

Give it a week so the ECU can adjust or do a ECU reset. Also give urself a week or two to calm down and not gun it all the time. Then if the problem persist retune