Sorry, but this is a bit longwinded...
So about 3 months ago my daughter called and said she ran out of gas. I bring a 5 gallon can and put it in there and it wouldn't start at first. It then started but ran REAL rough. I told my daughter I would tow it home later in the day. She ended up driving it aprox. 20 miles home and she said it ran rough all the way. I bought a code reader and it had 17 engine dtc's (misfire on 4 of 6 cyl., cam, crank pos sensor & correlation) so I figured timing chain.

Towed it to the shop i use and he did timing chains and then called me and said he started it up and it was still misfiring. Said he pulled the plugs and ran a scope down into the cylinder and bank 2 pistons had scars and marks on them so probably bent the valves. I said change the head, he said change the engine...so I towed it home. I tore it down to the block and the valves weren't bent and the pistons were not scarred up at all (needless to say I will never go there again).

I went ahead and re-did the timing and just for good measure, replaced all plugs and coils. Started it up after charging the battery(?) and had a ton of electrical codes. Replaced the bad battery, still had a ton of electrical codes which the hard code was now the alternator. Tested it and IT too was bad. Replaced it and started it just to have 7 engine codes, this time it was general misfire, cyl 1,3,4,6 misfire, maf and tps. cleaned the map sensor and throttle body, started it up and the only code was Throttle Position Sensor. Ordered a new one, installed it today, completed learning it, started the car and no codes...but it still ran like garbage, missing, ticking, etc. I thought about how long ago it was when I added the 5 gallons of gas with the gas can and it was June when i did that (yes, the car sat for a while). I went and got seafoam and added it to the gas, and also replaced some fuses that were missing (rt lo beam, bcm4 under the hood and rdo, stp light in the trunk). Started it again and now I am back to having misfire codes on bank 2 cylinders, general misfire, and also now a ton of electrical codes for doors, radio, and a checksum error code.

Is this an ECM issue? and if so, how the hell did it go from timing chains to bad battery, bad alternator, and ecm?!?!?!

I am ready to fill this POS full of tannerite, put it in my field, get out the 308 and watch it disintegrate!!!!! Needless to say, but I am pretty frustrated at the moment and could use some guidance, or a rubber room.

I should add that we have owned the car for 3+ years and have had zero issues with it until now.