morris29141

Has anyone had problem with a spark knock sound on acceleration. I have an 05GT with a Steeda CAI and an SCT perf tune (very mild), I run 94 octane Sunoco gas (or at least what's labeled that) and notice it primarily when cold even under moderate accell. The car only has 4200 miles. Any Thoughts?

[IMG]local://upfiles/31571/F00279A0DBEE4CB297A8180D45A2258A.jpg[/IMG]

The Ghost

Plugs probably begining to foul. Not uncommon with a canned tune. If it is plugs, it will get worse. Pull a couple and read them, it's free and will tell you a lot.

wmtheflash

I have exactly the same setup you do in my '06 GT. I have a canned SCT 93 octane tune and Steeda CAI and haven't had any problems after about 1,500 miles. My vehicle has around 4,500 miles.

Have you datalogged the knock sensor? You can also datalog and find out if the computer is pulling any timing.

I thought a sound that I was hearing was light knock, but now I believe it's just a characteristic of my aftermarket mufflers. I datalogged the knock sensor and it always reads zero. You can easily datalog on the XCal2 if you don't have a laptop. I do it all the time, SCT's website has good instructions.

The other thing to check is your intake itself. Just double check to make sure everything is installed properly. If any air is entering the system after the MAF sensor then it can certainly cause it to knock.

Also, if you have an 87 octane tune, then you could load that with 93 octane in the tank and see if it sounds the same.

I suppose you could also try switching brands of gas.