Since I have had my Quadzilla Tuner installed on my 03 DMAX 6 speed, I have been getting a bad vibration around 2000rpm....I am not running an after market exhaust........could this sound be back pressure building up in the Turbo Down Pipe???????? Sounds like it is coming from that area of the truck....

I highly doubt it is your exhaust. I would guess thats its your dual mass flywheel. Search about 6speed flywheels.

What gear?


I think that everyone gets a vibration in 5th...


Especially under load. It is the "straight through" gear...


I doubt that it is engine related...

I have already had my flywheel changed..... Didn't help any......


It usually does it in 5th and 6th gear...it gets worse when my engine is under a load......When I pulled a 4,500lb trailer it was horrible....It doesnt do it when my truck is stock only when I have the programmer installed.....*UPDATE* got the new 1.20 Quad update and it doesnt do it on the 50hp setting, but anything over that and it does.....but the more load on the engine the worse it is.......on a steep hill it is terrible...............im in good with my dealer so I told him what was going on and that I was running a power programmer.......we took it for a test drive and he seems to think that the programmer is causing so much boost that it is making my Turbo Down Pipe vibrate causing the sound..........what do you guys think??? He seems to think it could be solved with a aftermarket 4" exhaust......

Have you checked the downpipe bracket ?? They are known to crack ... You will have to pull the passenger side wheel well liner for a good look ...


Mac

From what I have read they fixed that problem on th 02's....But it wont hurt to take a look......

That would not explain why you are getting it in 5th and 6th gears only though...


Maybe an out of balance driveshaft?