I have intake and CBE no Tune! and I love it! I did not even reset my ECM when I installed the intake or CBE. Just let the car tune it self, took two weeks but the ECM will adjust!

 

Today i picked up some injector cleaner. My bro was told by someone that Seafoam injector cleaner works good, but the guy at the store told me it tends to eat away at o-rings so I picked up this lukas oil injector cleaner.

I also picked up some throttle body cleaner and going to see if i have time to clean them out tomorrow. Any other tips? Im just worried it might have something to do with my tune and really don't feel like having to pay to have it retuned.

 

Okay, so after that, no change. It's not that the car isn't running correctly, it seems as if its not putting down the same power.

So to add to the story, my SES light came on and coded to be O2 Sensor 1, Bank 1. I got home and peeked under the hood and under the car, and I also noticed the exhaust manifold cover on bank 1 (passenger side) is cracked almost in half (Split right across the air/fuel sensor, but this sensor seems not to be damaged). So now my question are:

1.) Is the exhaust manifold cover covered under powertrain warranty, keeping in mind aftermarket test pipes/exhaust?

2.) Could a bad O2 sensor cause this decrease in performance?

3.) I really feel like if I could put it back on the dyno, that could answer my questions, BUT I'd rather not pay another $500+ to have a dyno/retune if it turns out not to be the problem. What are some opinions?

 

I could answer number one for you. Im pretty sure the dealer wont warranty your exhaust manifold after seeing the aftermarket exhaust and test pipes. Best thing to do is put back everything stock to avoid any scrutiny.

 

I figured, but even the upper cover?

 

Its not misfiring? Is it winter where u are?
Replace the manifold with stockies or upgrade the headers. Something caused the manifold to break. Either winter conditions I doubt or stuck valve etc or a heavy foot in that case pay the stupid tax.
Call the dealership before you remove parts to see if your eligable in the first place. Either way manifolds gotta come off. I don't think a weld will hold it. Could be jus a crack, or internal damage. GL

 

No, its not misfiring. Im also not saying the manifold is cracked, just the cover. I doubt the manifold is cracked or damaged because im sure i would hear it coming straight from the cylinders...

 

Also if the manifold was cracked i would be losing all my backpressure resulting in more power loss than im talking about. My car has the power of a stock g37; not one with exhuast, test pipes, intake tubes/filters, and a uprev tune

 

Anyone?? Any help?

 

There is nothing wrong with your car. The way it works is very interesting... If you drive your G for 2-3 days without going high rev, the computer adjusts the fuel ratio and it outputs less power for fuel economy. The easiest way to change it is to reset ecu. However there is another way and its much more fun... Before you want to race someone, floor your car a couple times! It will adjust itself to give more fuel therefore more power

 

But even enough to lose to a stock 09 g37? Even before we raced I was driving somewhat hard for a good 5 mins ...

 

He means hard driving for a couple hundred miles.
Try 10/15 full highway pulls, in Mexico ( I'm not condoning street racing ) Ecu is adaptive, if you get stuck driving slow, cars reaction is horrible. Let it cool down then run it.
Btw, are you in warm temps, sounds like a oil cooler is in your future,
God luck with your runs against your friend. Or is it possible your friend is lying about being modded.?

 

We have a winner!

 

I would agree bad gas could be the issue of not spark plugs.