Engine Light is on agian

[PyroStar]

Ok so a few weeks ago I had a Random misfire code (P0300) I changed the spark plugs and wires. I also put cleaner into the tank, and got the engine light to go off. Since then I have driven some 600+ miles, I bought cheap spark plugs so I assumed they would go quickly. Well my engine light is back on with the codes (P0300) and now (P2610)the later code corresponds to the ECM. The return of the misfire code has me thinking about the spark plugs, they were rated for 6k miles, however plugs of that type I have found people online say they only last 1k-3k...
The (P2610) could that be a short? and if so could it be referring to the plug wires? I am not much of a mechanic but I can do minor work. I can usually figure things out with the proper direction, any insight would be helpful.
I cannot afford to take it in as the dealer wants some $80 just to diagnose it, and $80 something per hour that's not including parts.
I was pleasantly surprised when I fixed the last problem for only $40 and about 1 hour of work.
I also had a question about a youtube comment I read:

"the reason these engines get this misfire code is because of the valves in the heads. GM released a TSB about the issue. replace valves and head with revised units will solve the problem forever. the sea foam and copper plugs was only a temporary solution. it only lasted 5 months. now the engine light comes on every now and then. going to have to dig a bit deeper when it gets warmer."
Source: https://www.youtube.com/watch?v=pVmK...ature=youtu.be

And finally a mechanic told me sometime ago I might be read for a new waterpump and timing belt, I was asking about a different part and decided he was trying to make money so I didn't use him. However I did take it under advisement and made a inquiry at the dealer when I got my serpentine belt changed out. The told me they would let me know and never did. The random mechanic said the timing belt should be done every 60k miles, and while your in there you might as well always change out the Water pump.

Any how that's all I know, please and thank you for all of your help.

[avguy]

P0300 is unfortunately a generic code which has many different possible causes and solutions. I could list 10 of them, and others could come up with 10 or 20 other ones. But doing that would be pointless unless you are prepared to DIY this work yourself. And some tools (multi-meter, OBD real-time reader, vacuum gauge, etc) may be needed in order to diagnose and find the cause of the misfire. Assuming you don't want to become involved with a potentially complex DIY repair job, I'd recommend finding a good independent shop to diagnose what's going on with your Aveo. That's usually a much better choice than a high priced stealership.