Hi, My son bought a 2003 subaru wrx about 1-2 years ago that was modified to race. The transmission went about 8 months ago and when we had it replaced with a used one, the guy said the turbo boost was too large for the engine and the engine was probably going to go soon, it was also using oil. On the last inspection we had the engine leak down and compression tested and two right cylinders were not good and they said the engine was probably going to go soon. The engine blew up the next day. \n\nWe had a used engine installed and took it back to stock, taking the COBB tuner off. When we went to pick it up the engine stuttered in idle and when we down shifted it sounded very strange, the stutter goes away at a higher rpm. We had replaced the MAF at inspection time and they replaced the MAP, spark plugs and two coils when they installed the engine, also the ECU. They cannot find out why the engine still doesn't run smoothly and have told us that the guy who modified it had the wires all messed up and cut and taped and are saying that this may be the reason. They are sending us to another guy to diagnose the wires. We have a 6 month warranty on the engine. It has been at the shop for 4-6 weeks and still no answer. Before we go through a wild goose chase, can anyone shed some light on this?? I would be so grateful!!!