98 vortec 350 VIN "R" motor. is there ways to test the egr valve, or symptoms that it might be dead or dying?

 

thanks 1Gary. it does idle a bit rough, not horrid tho. runs great otherwise. could egr issues kick a misfire code?

 

took egr off, looks pretty clean. the pintle moves freely, very minor carbon. did notice there are three screws but ya gotta go thru the canister. is that possible to disassemble the whole thing without breaking it? also, while idling, i pulled the connector off, no change in rpm. is that normal?

 

gathered some data from my scanner. LT fuel trim bank 2 is -18 at idle, -11.7 at 2000 rpm. bank 1 3.1 at idle, hovers -2 to 2 at 2000 rpm. seems like all 4 02 sensors are ok, at least according to the data, so i'm suspecting 1 or more injectors may be done. still kicks p0305 at me, even after resetting. i assume that even one leaky injector would cause my trim levels to be negative on that side. or am i off?