Something that on the surface looks to be such an easy job can be screwed up WAY to easily.
Installing electrolytic capacitors backwards results in instant death.
Failing to top solder the caps can cause intermittent issues.
Failing to remove all the acid will lead to death.
Failing to use proper tools will cause board damage.
The list goes on and on.
For those of you that have never had the ECU out of the car, take 20 minutes and remove it and check to make sure everything has been updated. If the original caps are still installed, they will leak and it will cause failure.
Do this BEFORE you start having issues and the cost is $50 or less. Wait until you have problems and the cost is triple or higher.
If you want to know how to tell if your ECU has been working on, the two larger caps (1 is a 47uf and 1 is 100uf) will be fully seated flush on the board and have the manufacturer name of "Rubycon".
This also applies to non-turbo 6G Galants and 1G Talon/Eclipse/Laser.
This also applies to Automatic Transmission Computers.
Don't wait to long and don't cheap-out.