P1406 and New EGR valve

[CvilleDusten]

Hey, I have a 96 blazer 4.3 and about 6 months ago I replaced the EGR valve due to the code of P1406. The code never fully went away and would come up every once in a while. Lately, the code is on pretty much all the time. Does anyone have any idea what the problem is or how to check? Thanks

[Yogi]

You probably have a piece of carbon stuck in the valve which is preventing the pintle from moving freely.

Take the valve off. You will see 2 ports. one is exhaust coming in, and the other is the manifold vacuum port. The pintle, or valve stem, seats in the exhaust port of the valve, which tends to clog with carbon deposits. Clean the carbon deposits from the manifold port with a stiff wire. Put a short piece of vacuum hose on the valve and apply vacuum. Make sure that there is no carbon in the valve that is causing it to stick. The valve stem should move freely with vacuum applied. Start the motor for a few seconds to blow any loose carbon out of the port. Disconnect the battery ground cable for 5 minutes so that the computer code will be reset. Replace the cable and reassemble the valve with a new gasket. Autozone and NAPA sell a special gasket with a screen on it to reduce the chances of carbon fouling the valve.

[CvilleDusten]

Thanks Yogi,

I forgot to say in my post that I've done that once already, but it was a little while ago. The gasket on there now has the screen on it. I will buy another and clean the EGR again to see if that helps. I turned on the engine once with the EGR off but I was afraid to keep it running for too long without it on there. I will try again, and see what happens. Thanks buddy

[Yogi]

Quote: Originally Posted by CvilleDusten

Thanks Yogi,

I forgot to say in my post that I've done that once already, but it was a little while ago. The gasket on there now has the screen on it. I will buy another and clean the EGR again to see if that helps. I turned on the engine once with the EGR off but I was afraid to keep it running for too long without it on there. I will try again, and see what happens. Thanks buddy

No prob.

Welcome to the Forum and good luck!

[Easy48827]

FYI. THis was a problem on my Astro van. I had to pull the EGR 3 times and clean it- ran good for a while then check light would come on again. Turned out I had a bad o2 sensor. Replaced that and all problems went away and gas mileage back up to 18.5 average. Check your gas mileage and check for black soot in exhaust pipe.