Isuzu Ascender Check Engine Light

I Have A 2006 Isuzu Ascender. About 3 Months Ago, Cel Flashed Then Stayed On & I Had It Read-cylinder 5 Misfire. I Have Replaced The Battery...

My Instrument Panel Level Reads Empty Even After I Fill Up And Buzzer Sounds. The Indicator Will Steadly Climb To Full Then Back To Empty....

About 3 Weeks Ago I Accidentally Hooked Jumper Cables The The Fuse Box Instead Of The Battery...stupid I Know But Just A Mistake. I Blew...

Okay, This Is A Lot! To Start I Had To Replace The Head. So Bought The Head Got Someone To Put It On And Just Got The Truck Back. First...

I Have A Perfect Service History On My Car By The Dealer But Lately With The Economical Situation I Take My Ascender To A Diferent Oil...