New Member
Jan 1, 2020
United States
Hello! After having my car Dyno tuned with the SCT X4 Tuner, I have noticed a slight fluttering sound coming from the front of my car when in lower RPMS / higher gears. This sound goes away from either being masked by the sound of my engine or just going away completely; when I accelerate quickly up to 3000 RPMS. However, more force is needed on the gas pedal than what should be in my opinion. Without the tune, the sound is nonexistent. This sounds very dangerous, almost as if something is colliding with something / metal on metal.

MODS : BBK CAI, BBK TB + PLENUM, Magna-flow Exhaust

UNRELATED? : Cars battery seems to be wonky. Will turn over fine one time but will take a few seconds another. O/D light has come on and has blinked twice in the last week, but I could have just accidentally turned it off. This light does not stay on when I turn the car off and on.

* NOTE * I do not believe this to be pre-ignition as I’m using a 93 octane tune with 93 octane gas. It could potentially be, but I’m leaning to it being the torque converter?

*LAST* results from Dyno output were 242 RWHP + 284 torque ; 322 fwhp. Stock is 260 fwhp, so it doesn’t seem like there’s any power
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No sound at idle?
Nope! I got a P0782 code I believe? Trouble shifting from gear 2-3. Without this tune there was never a problem doing that. Must be a problem caused by the tune such as the engine running lean, etc. I do know the A/F ratio is whack and I’m a little disappointed with the tune job of the “professional”
@Jarn The tune shouldn't effect your transmission. I'd be more worried about the motor. An improper tune or spark advance can cause all sorts of shifting issues, but mainly relates to the combustion process taking place in the cylinders. Think of detonation before TDC. And I wouldn't be running 93 octane. The higher octane does no good for our cars since we have low compression, unless you have changed your heads to allow for a higher compression. Higher compression requires a higher octane for flame spark speeds. If the tuner advanced your timing then maybe he is having you use 93 octane but I highly doubt it. Hopefully you took it to a reputable shop.