that has been giving me anxiety attacks seems to not be what I thought it was. I believe that the popcorn sounding sporadic tick is coming from my pipes warming up. It was said in other posts that bad lifters sound like popcorn popping, my tick's were just probably not as loud as the poster was talking about... Also, I tried some cheap low octane gas and didn't make a whole lotta difference. I did find that it smells worse to me, and also that my pipes seemed to backfire a little more when letting off the gas. I don't know if this is the consensus with others, but more than likely I will be going back to the 92 oct. There was some concern of negative effects of 92 in this forum, but I will have to study this hypothesis more...