Hello, I bought my GT in 2011. Ever since I bought it, ive had detonation problems. Even when it was completely stock, it had to have 91 octane or it would detonate. Then, I did a PI swap with new heads and cams, plugs, intake, etc. Still detonates, even after a dyno tune. I cleaned all the carbon off the piston tops as well. Also, I replaced the injectors with new Ford replacements. The thing is, it doesn't detonate at all until it warms up all the way. While it's warming up, it feels so great and drives with a lot of power. But all the power goes away and detonation/pinging happens once it's at normal temperature for about 5 min or so. I've changed plugs to the tr6's, no luck. Removing 4-5 degrees of timing reduces the pinging slightly, but the power loss is significant. Should I buy a cooler thermostat? I have the stock 192 degree thermo in now. How about the MAF? Should I clean that? Idk what it could be. All that is left really is the MAF, EGR stuff, plug wires, and possibly a thermostat. I think there is something wrong, especially since I only produced 250 rwhp with stage 2 cams and new heads on the dyno. What should I do?