So I have been having this problem with rough idle and the power ******* out when I accelerate. I have 1/4 inch plenum spacer and chrome spacer. It has a nwp throttle body with a throttle body spacer and a 3.5 inch furookie intake. The exhaust is a motordyne tdx2 with art pipes. I noticed. The problem after I installed all the aftermarket performance parts I went by the motordyne specs to make sure the plenum was tight and also relearned everything. I took the 05 g35 coupe to the dealer and they ran tests vacuum leak tests and no codes were diagnosed. I've switched the trotted body back to factory and it still did the same thing after test driving it. What could this be?

 

You did a throttle body relearn again after you reinstalled the original yes? Same with ECU reset?

 

No. The ses light was not on but no I didn't try to relean anything yet. Do you think the injectors need cleaned or the fuel filter is clogged. I'm going to spray the engine bay with carb cleaner on more time and see if I can't find a leak.

 

No. The ses light was not on but no I didn't try to relean anything yet. Do you think the injectors need cleaned or the fuel filter is clogged. I'm going to spray the engine bay with carb cleaner on more time and see if I can't find a leak.

 

What kind of tests did they do? Do you have an auto or manual. The manual might require an exhaust relearn, which only the dealer or if you have consult can do. What is your idle rpm at?

If you have an obd2 scanner you can monitor fuel trims to see if the ECU is havingto add or subtract fuel.