ok, to answer ur question straight. this is a way of cheating and most of you guys will hate me to say this, but im gonna say it. IMO, easiest way to ruin the engine is by draining all the oil out of it and then turn on the car. when the engine starts knocking(fuckin up), turn off the car, add some oil to it. reset the ecu, turn on the car, let it idle for a while, and then drive a little. call toyota about engine knock and hope theyll fix it.
now some of you might say, "oh how dare u, thinkin through how to do all this and that, you a thief." the reason i thought about this is because toyota is a bitch. if they are asking for 19,000$ for a 2000 gts with 56,000 miles on it, is that a ripoff? so i thought that if i buy the car overpriced, im gonna make them change my engine or tranny, or else both.
btw, this is my last resort if i cant find an affordable celica. i wouldnt recommend anyone doing this though, but that answers ur question