i just took her out for a late night spin and the ses light came on so i took her to autozone and had it checked.. well it threw a p300 code (multiple misfire), but its funny cuz the guy cleared the code and itwent away along with the vibration..hmmm.. so tomorrow im going to change out the egr valve as well as that wire that goes from the opti spark to whereever it goes ( i remember that wire being "out of shape") also i wanted to ask everyone what kind of gas mileage they get on their lt1 motors, only upgrades i have are one that dont impact the engine ie; aluminum drive shaft/ rotors etc etc.. im asking cuz im getting about 215 miles to the tank with city driving.. thanks in advance! ill keep everyone posted!

 

I get about 18-20 city mpg when I'm using 1st, 3rd, 5th shifting keeping rpm's low. When I'm getting down it's much lower. I'd be amazed if you're getting less then 15 (non revs driving)

 

well be amazed cuz i get 13/14 sometimes.. im taking her in to a shop tomorrow to get the misfire diagnosed.. ill let everyone know..