I made a post on this a while ago and i went on vacation and i can't find the post anymore so please dont flame me.

Anyhow, everytime i hit boost i detonate, i know its not my pressure sensor, i changed it wiht one i know was good and did the same thing. I today changed my TPS sensor, yeah it runs better but it still detonates. I check for vacuum leaks and couldn't find any. I really dont know what else to check i have an aftermarket turbo and an afc and i was boosting 15 psi and if its anyhelp when it starts detonating my air fuel drops like a rock to lean. Also if i go slow enough i might be able to get 1-3 psi

 

turbo upgrade, 15 psi of boost, stock intercooler, and zero tuning will cause detonation.

No listed fuel mods... DEFINITELY causes detonation.

 

I found it, I fried a resistor in my ecu because some wires are touching im resoldering in tomorrow if i get time. Hey ran like a dream before this.

 

damn and your motor is still good??? I know if that happend to me I would not be that lucky.

 

scathcart has nailed it, this is a textbook example of bad modification of a turbo'd engine. Big turbo upgrades come after you upgrade fuel and intercooling, not before. I can't believe you're actually asking why you're detonating. It's certainly not because of a fried resistor...