EGR bypass
 

On a 1996 4.3 blazer. I removed the egr line from the exhaust manifold and intake and using the existing line I cut it in half and removed the fabric heat shielding. Cap the exhaust manifold with a #10 gas NG cap. With the line reinstalled into the intake straighten to a vertical position and mark a position near the flat position on the bottom of the plastic air inlet housing that attaches to the throttle body. Mark the line to a position that about 1 inch of the line would protrude into the plastic housing. Remove line and cut where marked. Remove the plastic air inlet housing from the throttle body, flip it over and carefully drill a hole not to exceed the size of the metal tube , it will be near the edge of the housing. Using a couple of rubber o rings slipped over the metal tube to seal to the plastic housing carefully reinstall the plastic air inlet housing with the metal tube inserted into the drilled hole. Now you have cool air passing through the egr valve when operating and cel light will not be illuminated as the egr valve does not know if it’s hot exhaust gas or just oxygen flowing through. Will still pass inspection, no cel and no longer have the carbon buildup occurring in the plenum chamber as before.