Replaced the ECM for a little over 1000 a year ago in Colorado Springs. Toyota gave us trouble ordering and delivering the right one. They were very rude to the shop that did the repair for me (for less than half of the dealership's cost). Suddenly, without any notice from my thermostat, I must've blown or popped the head gasket. A nice stranger noticed steam coming from the passenger side and let me know. I started hearing a gurgling in the heating coils every time I stopped at a stop light. It was confirmed that I had a leaking gasket.- A mechanic friend of mine who had a scope-like tool was able to see where it was coming from. I kept water in it and made sure it never overheated before taking it in. But apparently it did overheat and caused more damage. Now the Toyota Dealership (in South Carolina) says the headbolts are stripped and the threads that are deep in the short block are stripped and the short block has to be replaced (in addition to the gasket, and all the other things that go into having it replaced- especially the LABOR!). I went in to have them show me exactly what they meant. I could see where the leak had worn away part of the seal, although I couldn't see into the short block to see the stripped threads that they said were also corroded! They claimed that they were unable to get the tool and toolman to make new threads because it wasn't work they could guarantee.- Then bolts would have to be slightly bigger and it might not work well when it's put back together. It's risky getting a used engine, because then I could run into the same problem all over again! The new short block that was made in Japan and sitting on a shelf in Florida is going to cost about 2000. I asked another expert mechanic about the stripping of bolts and he said they did it by tightening it too hard. The short block is made of aluminum, which is soft. Chances are the Toyota dealer stripped the bolts on accident, and then had to make it out to be corrosion to cover their tracks. I did receive phone calls that first asked me if the engine had ever been worked on before (no), then to tell me they were replacing bolts because they were stripped (no problem, they were $8 a piece), then the third call came with the really back news: I need a new engine (the short block) because the stripped threads were corroded. So much for this wonderful Toyota being paid off next month? I have to sink in almost 5000 to fix the problem the right way? I take very, very good care of my car. I've always had the oil changed in time and had it serviced regularly. This was a shock! A year ago I thought I was going to have to replace the ECM and the transmission, but it was only the ECM. -By the way, the dealership in another state where I had the ECM replaced charged me 100 bucks to tell me this, but when I took it to a "Mom-and-Pop's" place, they had proof that they had never checked my transmission because the original seal was still on it, AND my fluid was perfect color with nothing in it? They ran all the tests and found my transmission to be fine. Darn those computers!