hello,
you can be for 99 % sure that its your ECU. A friend of mine had this problem too. No check engine light, never. And at one day, the car wouldn't start anymore. We checked EVERYTHING, then he came up with that fact.(that the check engine light, never went on)We placed a ECU from a car he had for spare parts, and he worked perfectly again. By the way, Open your ECU up. One of the parts inside that ECU is leaking, i am willing to bet for that, for almost 99 %. Every ECU from the 6G galant, starts leaking, when is hard to say, but it WILL happen, you can count on that. Check this picture, about what happens, when your parts of the ECU leak:
picture leakingIts a common problem, and wel know, within the (at least the dutch), galant community.
I think thats your problem.
By the way, i heard this, from this leaking part of the ECU also about 1,5 months ago. But i checked mine ECU and it's leaking to(galant 2.0 GTI 16V).
So check it!
There's someone on this forum, who fixes those ECU's, wich are leaking! Use the search.