i have a 2003 ram 5.9l v8 it start today when i go WOT, once i hit 3500rpms it starts misfiring.
I was running a superchips flashpaq on it but now went back to stock. could this be why? i have 52mm tb, 1.7 hs rr cai, jba headers.

Could be ping u hear . Did u fix your plenum with those mods ?

No i havent but it looks good, all dry

Might be the cat starting to clog. Your mods in you signature say dual straight pipes, but are you running cats?

What exactly is a power wire?

Yes i am running a cat. The power wire is a wire that plugs into your intake temp sensor to trick the computer to thinking the air is 20-22 degrees cooler. I dont have that anymore.

I woukd have thought a misfire would be more electrical. How does the gasket make it misfire or a cat?

Plenum gasket will allow a vacuum leak..... throwing off a fair few sensors, and ending up with a too-lean mixture in the cylinder. So you get either spark knock, or, no fire at all.

Low fuel pressure will give you the same behavior, as at WOT, the O2 sensor is ignored.

Ok. I have no codes up. I would think that my check engine light would be on

A misfire should set a code.... if it happens often enough. If you are on here posting about it, I am going to guess that it SHOULD be setting a code.... might wanna take it to the local parts store, and see if they can read pending codes..... does the CEL test when you first turn the ignition to on?

Yes it comes on. It only does it when i really get on it. But i can sit in neutral and rev it and it wont do it.