What octane is everyone running? I'm runnin 89, took care of some chitty-chitty bang, bang, noises during startup. I read another post awhile back, and another guy was having problems with his engine making a lot of noise when it was cold out, so he ran 89 for 5 tanks and it went away. He said after the 5 tanks or so, he put 87 back in it, and the noises came back. Been runnin 89 since and no issues.