Alright, here goes from the beginning. I recently took possession of my dad's 'mid-life crisis' 1989 Corvette. He bought this car when it was a few years old and taught me how to detail and care for it on the promise (fast forward to now) that I would get it. The car was always garage kept and floorboard/dash/seats always covered. Car has 65k on it. Well, while I was on active duty he lost interest and the car was moved outside..... and sat. I towed it up to my house, replaced the battery, flushed and filled the oil a few times (after the first change there was a slight milky look so I was worried about residual condensation in the engine) and replaced the fuel filter. The car ran...... alright. I took it down and sprayed it to remove the heavy grime. The car ran and then died. I had Chevy replace the cap and rotor, plugs wires and coil. They diagnosed fouled injectors so I towed it home and used, thank you to all members of this forum for the recommendation, Jon at FIC to put some remaned Bosh 3s in. The car now runs pretty good but the dealer warned me that fouled injectors in an engine that has been run can ruin the ECM. The car runs good when I reset the ECM but when hot the CEL comes on and the idle runs between 1200-1300 RPM. Also the '1-4' light is on and no fuel econ data is displayed. Are these all signs of a bad ECM? I just feel after all of the $$ at the dealership for plugs, wires distributor cap/rotor and injectors it just isn't running as good as it should be and want to get the old girl right.

Also there is some spark knock which I am not terribly concerned about, yet. The fuel in there wasn't terrible old, I pulled about half out, added some sea foam to dry it just in case and some octane boost in case it started to lose that and then pressed up with fresh premium. So once this tank is gone and I know I have fresh gas in there I am hoping that goes away. When I sea foamed the engine I saw some of that 'healing' smoke coming from the manifold which I am guessing might be corroded. I need a full exhaust inspection as I fear there might be other issues just from listening to it from behind. There’s also a little more heat on the floor than I remember….. Catalytic converter possibly. Would that be a concern at this age?

My two questions are is my first concern really an ECM issue and my second is what other thoughts/actions should I be taking?