I have a 1985 4Runner. 22re 5speed. Complete rebuilt motor, new denso o2 sensor, new denso plugs, wires, cap, denso reman afm, adjusted tps, correct timing, new silicon vacuum hoses, so on and so on. I'd been having this strange miss and hesitation in 2nd gear at light throttle around 2100-2700 rpms. At full throttle it runs great. I put a piece of a coke can between the egr valve and the intake plenum and that got rid of the slight hesitation I had. There is still a little bit of popping in the exhaust but it's barely noticeable. Should I replace the egr valve or just leave it blocked off since this is obviously my rough running problem. Also are there any other components of the egr system that would need replacing or just the valve? I don't really understand all I know about the egr system.

 

the most basic test for egr functionality is to put vacuum on the hose that's plugged into the top of it... if it's working, the engine should stumble and/or die... even just sucking on the vacuum hose is enough to do it.

how about taking the coke can blocker off of the egr, and pulling the vacuum lines to it... plug 'em up, and it should behave the same as if it was blocked off? unless there is a diaphram leak or something in the egr.