Ok. lemme start off buy telling you of my car. They consist of a JLT intake tube and stock filter, FMS underdrive pullies, and a Steeda shifter. the car had 68k on it. Its a 99 35th anniversary #62 convertible.

So I noticed i have a ping/knock when reving the car in idle when it is warmed up and has been driving for a little bit. I cannot hear it durning accelartion, but it could be me just not hearing it. So i tried the basics, fuel filter, cleaned MAF sensor, and used a can of seafoam threw a vaccumm line. "smoked like crazy "

still did it. I know its detonation because it goes away with 93 oct, but still does it with 87-89 oct.

Another problem is, say im cruising on the highway in 5th gear for 10 mins or so, push in the clutch and rev it. It has a brain fart and will not rev for smooth, then revs when the rpms get higher. It stumbles.

My ecu code is JKU3 i belive..

Please help before i go CRAZY!

Thanks Matt Labukas

well sounds like you timming is advanced to much for the lower grade fuel. just back it off a few deg. and see waht happens.