1999 Isuzu Rodeo Question P0401

Does the egr valve work? Try applying vacuum to it and see if the idle changes. Double check all the vacuum lines. If your still having trouble tomorrow I will check to see if there are any bulletins, and I will look up that system. Its hard to memorize every egr system in every kind of car. I will check back to this post tomorrow. Hope this helps

Good luck applying vacuum to that valve.

This vehicle uses the same digital egr valve that gm uses on its 4.3 vortec motor.

2 things

1. Did you use an oem valve with a new gasket?

2. Chances are the egr passage is blocked close to the intake side. Blowing into the passage will not help, the intake will need to be removed and cleaned.

I just looked that up. It is the gm style one(im glad someone is keeping an eye on me) there are a couple of other things I would check. Lightly pull on the wires at the plug to see if one is broken inside the insulation, (very common) also you can remove the valve and have someone start the car for a split second, if the passages are ok there will be a loud exhaust noise and a high idle. Ive never had to remove the intake to clean the passage ways, I just break off the chunks of carbon and blow out the passage way. They updated the egr gasket with a new one with a screen on it, id use that one. Check back with us.

A piece of coathanger works well on the ports.