2004 g35x AT with Berk HFC and Stillen Cat-back.

When driving in Drive, the shifting is happening earlier 2k-2,5k range, making the car a little sluggish. Doesn't even stay in 2nd long. When I manually shift, the car goes fine. Also, the mpg is less then stock, but it's worse when I drive it in D.

Only other mods I have done, are intake, and the grounding kit (no ground wire to transmission).

Any suggestions in getting the tranny to shift better?? besides going back to stock

Thanks,
-Carlos

 

Reset the ecu by unplugging the battery overnight.

 

K I can try that.

 

If the battery trick doesn't work follow the instructions in this thread for a true ECU reset. Takes some practice to do right don't give up after a few failed attempts.

http://www.6mt.net/forum/performance...rocedures.html

 

None of the wires under the car got damaged during the install did they. I just put a Megan racing one on my car on Saturday with no problems.

 

I had an engine code for front driver side o2 sensor, after the exhaust install, so I replaced both of the front o2s. Other then that, I've had no codes appear.

Hopefully tonight I'll have a chance to unplug the battery overnight, but I might have to wait till the weather is over 20 in the early morning. -2 this morning hahaha.

 

Sounds like the car is going through its re-learning process after the o2 sensor switch. If the unplugging the battery trick doesn't work I'd say give it a couple weeks/ few hundred miles and see if it works itself out. That's what I've done when I was getting a code for my crank position sensor, I replaced it and left the cel on till it turned itself off in a few days (or a week I can't remember lol)