Caused by carbon buildup. I have done two treatments of using around 1/3 of bottle of Seafoam each time and still pings a lot and I get around 2-7 of kr at all rpm's and any amount of throttle. So performance is down big time. Should I just keep using more Seafoam until the pinging and kr stops? I have put on two nice smoke shows.

 

You sure the carbon buildup is what's causing it? Especially after running SeaFoam thru.

My guess is that the DiabloSport tune is probably part of your problem. I had a little problem with pinging after Diablo tuned my car. Usually it was just during the day, when it was fairly hot...at night, it was fine (this was during summer, about a 6-8 month season here). I don't have a problem at any time now, being that it's only in the 70s during the day.

And what's the highest octane you can get over there? I believe I've read that 91 is the high at most gas stations in Cali...? I was running 93 and having problems so I can definitely see you having problems with 91.

Try bumping the timing back a little and see if that helps. Or try some octane booster, I know it's usually a waste but if you're only running 91 then it might get you up to 93 or 94+, which might help. Lastly, you could try setting the car back to stock (programming) and see if you still have any knock.

 

The stock tune has been in the car for a couple months now and the dealer reflashed the pcm already. It pings even in 40 degree's. I was up in the desert during christmas in 40 and below weather and it pinged. We only have 91 octane fuel here but I have been using that for over a yr and it didn't start pinging until I started driving alot. I have tried all brands of gas and it doesn't matter. I am almost 100% sure it's pinging because of carbon since I made a nice white smoke show today after using the Seafoam. I have a catch can system I made using a air compressor filter and it collects a descent amount of oil, about 1 -2 teaspoons in 400 miles. Time to go to the dealer and be a jerk to get them to fix this and all the other problems. By the way my LT's are negative and 0 at wot . Also the plugs are black from all the carbon. I have a set of NGK's 55's coming in the mail tomorrow but first have to clean the motor out. I have 1 and 1/2 cans of Seafoam.