ive been fighting a random misfire for about 6 months now, and ive narrowed it to a lean condition on the passenger bank (manifold glowing, new cats), can i run the fuel pump with the fuel rail off the manifold to see if i have a leaky injector(s) or are the clips not strong enough to hold them on with 41 psi fuel pressure

 

Don't know why not? Am a little confused though. Why would a leaking injector cause a LEAN burn. Are you sure you don't have an EGR or other vacuum problem?

 

i forgot to mention the engine has to crank for several seconds on startup hot or cold and when i connect the fuel pressure gauge it makes 40 psi but with key off it loses pressure quickly, im tryin condemn either fuel pump check valve or injectors (fuel pressure regulator is 3 days old), so im thinking if the injectors are worn enough to leak then they may be ****ed up enough not be opening all the way

 

egr valve is brand new too

 

Yes you can check the injectors by just pulling the fuel rail off the intake manifold. Blow off the intake around the injector holes so as not to drop dirt in the holes with the fuel rail off. Also put a light coating of motor oil on the injector o-rings when reinstalling the fuel rail.