As some of you probaly know, the "great" state of californina has the lowest quality of gas. I'm in the bay area too so I'm paying $2.50+ a gal too. Anyway, the highest octane we got is 91. The guide recommends 93. I know I can run 87 if I wanted too, it would just run like crap because the timing would be so out of whack. However, if I'm in a cruising gear doing about 2k-3k rpm and I dip into more than half throttle, I hear a pinging that quickly goes away. When I ran at the track a month ago, I mixed in a few gallons of 100 oct and it went away. OK, problem solved there, but I'm not driving to Sears Point to get a fill. The big problem though is that after "spirited" driving, the SES light comes on. Could it be going on because of the lower oct? Anybody else from california have similiar problems?

Also, I read a thread that dealt with the belt tensioner going bad and creating a slight noise at idle that goes away as you accelerate. Sounds like my car. Is this a big job? I got no problem getting into it but if it requires special tools or precision measurements, I'll take it to a shop.

 

No SES light or pinging on my car or my wifes (both LSx motors) using 91 octane CA gas. Do you think you could have carbon build up?

 

Belt tensioner swap is easy, with common tools.