What exactly does it sound like? I got my sct on the 91 tune with a half tank of 87 and half of 89 but I haven't heard anything but I honestly don't know what to listen for. Is it something I'll know when I hear it?

 

Marbles rattling in a can when you push the gas is the closest I can think of.

 

I've got a small exhaust leak at the header and my truck is loud so I really can't hear that well. Will only do it if I'm on it hard? Is it loud?

 

The way i could tell was let the truck shift into OD at about 40 and the give it gas to put it under load. Don't let it downshift though, just want to let it lug a little. My marble in the can were very noticeable even with my exhaust.

 

It sound eerily similar to an exhaust leak or lifter tick. perhaps a bit louder. The volume really depends on how out of whack the timing or A/F ratio is.

 

guys, I could feel spark knock.. it's like a slight hesitation while accelerating- as if you're putting the engine under a ton of load. I could feel it kinda sputtering, and knocking at the same time... mine was due to iridium plugs.. it's a guarantee in my truck- I use those plugs I get knock- period..

 

I'll check it when I get my truck back. I'll fill it back up with 89 and throw some octane booster in and see if anything is different.

 

sounds like metal popcorn, popping is the best I have for it, and its pretty noticeable when you hear it, you should only get it under heavy throttle or load