A few days agp when I started up my Z to go to work, it started fine, but I heard a loud hissing noise. After I backed out, I stopped and watch my temp gauge to see if it was getting hot. I popped the hood and everything was fine, no broken hoses or leaks. Driving down the road the noice continued, not getting any louder. Then when it stopped the engine felt like it missed or something and then my ABS, Break, Low Trac, and SES light came on. The SES and LT light went off after a couple seconds. The ABS and Brake light stayed on until I pulled over and checked things out. Again no leaks or anything. When I started the car back up, it acted like the battery was low and had a little bit of a hard time turning over. Also, a buzzing noise came when I started her, then stoped after it kicked over. My question is, could my optispark be going bad? After I started it up again, there was no loss in power or anything. If anyone can help, thanks.