well, things just keep getting worse; while I was coasting to a stop at a stoplight, my speedometer suddenly drops to zero even though I was still moving. attempted to pull codes while the speedo was dead, and got absolutely bupkis. a little later I managed to pull a P0700 and a U0001, as well as the dreaded P0420. although I have noticed some corrosion recently on my negative battery terminal, and I noticed this afternoon after work that it was cranking a touch slower. i'm starting to think that maybe my battery is on its way out which could likely cause the electrical system to freak out. (there have even been times where my HVAC and Radio conk out, but they came right back after a key cycle.) any opinions would be appreciated, as I'm starting to tear my hair out and lashing out at people because of this.