Dude when you have gone through everything as I have done there is to go through and you are still having issues there is a posibility that you might have a ECU problem. I know this because I have been there before with a Mitsubishi engine. The check engine (Idiot light) is a good tool but can't alway's be relied upon for the answer. This is why I have asked if anyone knows of a way to test the computer.
There's a sticky either in here or in the B14 subforum telling you how to manually pull ECU codes. All I know is that mine has thrown one code the entire time we've owned it (about 4 years now). What types of problems are you having? Others on here might be able to help if they knew more what was going on. But what I suggested doesn't really test the ECU, so I don't know. I guess you could pull one from a car in a junkyard and see if that fixes it (same engine, same transmission, either federal or cali depending on what your car has, etc.).
I have spoken with other's in particular Ian who in my opinion is one of the more informed on this Forum. I have been through just about everything my issue is the car has a hard start problem but once warm It starts easy. I have no CEL's I have used a Snap On Scan tool that is top of the line and there are no codes. This engine and trany were swapped by me and have very low mileage. The problem of hard start is accompanied by low power. These problems were there on the 200k plus combo that was original to the car hence my thoughts on the CPU.
Well, you can always pull one from a junkyard and try it out, but that's not necessarily a guarantee. And I didn't know that you had spoken with others on the forum. All I had seen was the original post and thought there was nothing wrong with your car.