P0401

Gm blazer 1998 how clean egr intake passages. Have removed throttle body on ford's. How to clean on this engine. Thanks in advance. 4.3 engine.

I think your best plan is to remove the EGR valve and possibly the upper intake plenum, as in the plastic part of the intake that the throttle body bolts to. That'll give you access to both ends of the EGR passages. Be sure to buy gaskets for the EGR valve, the plenum AND the o-ring that goes around the injector connector.

That said, are you sure you're dealing with plugged passages? :huh: Because I've had the lower intakes off of these engines many times, and never found their EGR passages to be even remotely plugged. This is probably the only EGR system that never really suffered from severe plugging.

Usually, I find that a.) A piece of carbon from the exhaust found it's way to the EGR valve, or b.) Someone installed a 'screened' EGR valve gasket, and that's become plugged. I've also seen the EGR tube from the exhaust break in two, but that's less common.

In all three cases, it might be as easy as pulling the valve off for a visual inspection.

Have egr on no stall. I would think a sticking pintle would trigger a egr position code.

Oh yeah, you'd get a P1404 or P1406 if the pintle wasn't performing. But I've seen carbon chunks big enough that they don't go into the valve, but obscure the port enough to cause a P0401.

All the more likely if someone installed a 'screened' valve gasket. Like this:

www.amazon.com/Dorman-47007-Screen-Gaske...rtment/dp/B000CSZHA8