I had the same problem on a 1998 GT. Engine light came on because of misfire in #4 cylinder. Took it to the dealer and they couldn't find problem. Adjusted timing(even though I told them not to because it had been done 1 wk earlier), charged me to change plugs and didn't, changed coil, plug wires. Cost $900. Result: We can't find what's wrong, but if you want to we can charge you an additional $1000 to tear the engine down and see if we can find anything with no guarantees we'll find the problem. Decide this dealer didn't know what they were doing, so took it to another. They called me 4 hours after dropping it off and said the problem was a bad injector wiring harness. Paid $500, took the car home, next day the light was on again and still running rough. Took it back and they tried a top end cleaning. Picked car up 2 days later and the next day the light came on again. Took it back and they had it for over two weeks before telling me that the wrist pin in cyl #4 was bad and that the entire engine had to be replaced. I asked why they couldn't just drop the pan, pull the bad piston and replace it. Apparantly, the way the boxers are made, this is not possible and the entire engine needs to be disassembled to change a piston! After arguing with the dealership, the owner of the dealership, the district rep, Subaru customer service(I would have been better off hitting myself in the head with a hammer than talking with CSR)they agreed to put in a short block for ONLY $4000. Would have been $5500 if I hadn't been a pain in the arse. It took 4 weeks to get the block in because they were out of stock (wonder why). I then started to rad about piston slap in the 2.5 litre engine. I bought this up to the service manager and the regional rep. Neither would admit they had heard anything about it. Piston slap, if you don't already know, is the piston rattling back and forth upon startup until it swells and forms a tight seal. Does a piston moving back and forth sound like something that would make a wrist pin go bad? It sure does to me, since this is what holds the piston to the connecting rod. HMMMMM, coincidence, I think not. But, try to get anyone at Subaru to admit the problem exists.I originally took the car in to the shop the second week of January, got it back the second week of April and traded it the next week. To top this all off, the service manager at the second dealership told me that the reason my engine had to be replaced was that I had installed a K&N filter and the engine was getting too much air. I let him know that either I wasn't as stupid as he thought I was, or he was more stupid than I thought he was. Total cost, approx $6,000 and several years off my life span. Bottom line: This was one of two Subarus I owned at the time with plans to own a 3rd and 4th in the future. I sold the other one I owned (99 Outback) 2 months later and will never own another. At least you know you're not alone. Oh, also on both cars, the windshields had at least 10 chips and 2 cracks in each.