hi all i have an 98 civic ex with about 70k miles during acceleration i can hear knocking/pinging sounds form the engine.i think is call pre-ignition knock.it get lower if i use premium gas.anyone have this problem and know how to get rid of it? thanks

 

retard the timing a point.

 

Tune up and check/adjust timing

 

With 70k miles on it it's more likely timing than a knock issue.

Are you getting a cel? The ecu could pull timing because of that. If not the belt could have skipped a tooth.