ECM going out?

[Chevylicious002]

I have an 01 Tahoe. It wouldn't start, we didn't hear the fuel pump kickin on, so we changed it along with filter. Still wouldn't start. So we reset the ECM (disconnected battery cable for 10min) and It started right up. Last night it wouldn't start again, so we did the same thing, and it started. So I'm assuming the ECM is going out?

 

[TheHoe01]

What does it do when you try to start it and it wont? Crank or no crank? Spit and spuder?

 

[Chevylicious002]

It'll crank, but won't start.
Husband cut an access panel for fuel pump, and before he messed with anything, we tried to start it, & it started right up. So we're guessing maybe there's a short in the wiring somewhere.
A couple times we've noticed when accelerating, the engine kinda sounds like it's wavering?
Also, couple months ago we had it checked out at AAMCO, & they said there was only 1 code, a lean code for bank 1.
Idk if it makes a difference as far as air flow n whatnot, but we also have straight pipes, no muffler. Previous owner unbolted it from right below the back seat.