2002 Mitsubishi Galant wont start 2.4L

Ok Im a advid mechanic but Im a little stumped. Rule out the battery and starter cause it cranks but wont start. Yes I do know it has those chip keys but its not it. First I thought I wasnt pumping gas but usually I hear fuel pumps pumping gas when you put the ignition on, but not this car. It comes on when you crank it. And ruled out the spark plugs they are new and they have spark. All fuses are ok. What doesnt make sense is when I took it to Autozone for a check engine light but when they tried to hook it on they said the plug under the dash was not supplying power to it. Funny weird I said. But question is, can I rule out the Brain of the car and what else can I check to see whats causing it not to run? Oh and the vacuum lines are ok too