Hi, recently i purchased an 86 Camaro sport with a 305 Q-jet, and it has been a blast. when I bought it, it had the check engine code for bad 02 sensor and bad map sensor, and I replaced those and the codes went away. for a few days now however, both codes 41, and 53 have popped up, and i'm not sure what exactly it means, since they both could mean many things. I suspect it may be a bad ecm or icm,because it seems to be running rich (bad gas mileage) and it will diesel at certain rpm, I am new to this car, but know how to work on vehicles, so if anyone could point me in the right direction of what to replace/diagnose, I'd be very thankful

P.S I forgot to mention it has an Edelbrock Performer intake and camshaft as well, I don't think that would effect the ecm, but just thought i'd share that.

Code 41=Cylinder select error (Calibration setting does not match # of engine cylinders) or Faulty or incorrect MEMCAL. Generally an indication of a bad connection to ECM somewhere if car has been running.
Code 53=Voltage at ignition switch (battery) above 17.1v or lower than 8.0v.
Likely there is a less than solid connection to the ECM.