Oh I forgot to metion that every once in awhile the ceck light will flash for a couple seconds then stays on

 

What codes ya gettin'?

Might wanna replace the O2 sensor just on general principles......

 

Misfire on 4 cylinders I don't remember which ones but it was both sides. Why would the CEL flash ?

 

CEL flashes when cylinders are misfiring. If they misfire often enough, it sets a hard code. (at least, that's how the GMs worked......)

If you are getting a random misfire code as well, might be time for a tune up. When mine was doing that particular trick, the dist cap and rotor were in pretty bad shape.

 

Any knocking or pinging? Have you tried rerouting the wires according to the TSB in the FAQ?

 

already did a tune up

 

Check plug wire routing is suggested above then.

 

but my thing is the wires weren't routed like this from the factory so why would you change them ?

 

Were the wires you replaced factory wires??

TSB came out after the trucks had been on the market for a while, to correct misfire problems associated with the plug wires engaging in a bit of "cross talk".

What flavor of plug wires did you get??

 

autolite I want to say