I have a quick question... My car has been getting CEL's and at the same time my battery completely died and had to have my car towed to the dealership, which I thought was releated to the CEL, like a non-charging battery or what not.

My question is when your battery dies are the codes the CEL generates wiped out? or are they stored in some sort of stable ROM in case someone unhooks or changes the battery or otherwise starves the system of electricty?

I am kinda pissed at my dealership right now and I want to know if it was possible for them to properly diagnose my CEL or did they just take the shortcut and assume my battery was the culprit?

Also... just some backstory, after bringing in my car, which they had for 2 days, they completed the recalls and changed out my battery, however now there is a scratch on my leather steering wheel, obviously I am still getting a CEL, the car pops when I idle now (no mention of an ECU flash on my warrantied bill), my sun visor is still broken and I now have a mysterious new rattle when I drive.... GRRRR.