02 Sierra 1500

As of today my truck has started pinging and knocking.
Under moderated acceleration its not too bad and idles okay.
The problems occurs at high RPM, it's very noticable and after a few seconds seconds the service engine light will flash and then dissapear once the RPM's have dropped.
Thanks, JCC

Get the code read (could be more than one). If the light came on, there will be a code stored.

//2000CAYukon

This place is horrible, I'm out!

P.S thanks for nothing

Engine misfire, when the SES light flashes you have a catalytic convertor damaging problem, hence misfire, too much fuel not being burn and later damaging the cats. Get the code pulled, and start looking over ignition and fuel components for the misfiring cyclinder(s).