Hey, I have a 96 4.3L blazer 4x4 107,000 miles

First: I replaced the EGR valve maybe 6 months ago due to the code of P1406. The code went away for a while, then started popping up every once in a while, and now its back on for good. Is there anything else besides the EGR in relation to P1406? I heard it might be something to do with the EVAP system. I put a new gasket on when I replaced the valve. I even took it back off and sprayed carbon cleaner into it. No help. Any ideas???

Second: About a month ago I replaced the Idle Air Control Valve since whenever it was in Park, it had a very erratic and high idle, so bad that it would jump when I put it in gear. Everything was fine for a while and then it started happening again. Sometimes it'll have an erratic idle and other times it won't. It's only when it's in Park though. Does anyone have any ideas or solutions for this???

Replaced Parts: EGR, Idle air control, Throttle position sensor, 3 oxygen sensors
new spark plugs, distributor cap and wires about a year and half ago.


I would appreciate any help from anyone!!

 

When you replaced the EGR valve, did you clean out the supply tube? If you did not, then it is possible that a chunk of carbon made its way into the valve and plugged it up. There is also an EGR gasket available that has an integrated screen on the supply side.

If the EGR valve is free of carbon, you may want to inspect the wiring harness for damage which may cause either problems with setting the EGR valve during operation or problems with reporting its location during operation.

 

No, I did not clean out the supply side. To clean it, should I just spray carbon cleaner down the hole and brush it? Also, I do notice that when I unplug the wiring to the EGR, the connector is a little moist. Could this be part of the problem like if the seal isn't working? Thanks for all your help!

 

Bumping this up, I could also like an answer to the last reply even though its an old post....

 

Answered in quite a few other posts. Just use a brass pipe cleaner and some carbon cleaner down the supply tube. Then start the truck with the EGR valve off and the port into the intake plugged to blow out the loosened carbon.

One thing that may be necessary on the early OBD2 trucks is for the EGR valve to relearn its zero position. This is accomplished by disconnecting the sensor, turning the ignition on, clearing the code and turning the ignition back off, then plugging the sensor back in. The PCM will then cycle the EGR valve to relearn the zero position. There may also be a PCM update to reduce the sensitivity of the EGR position circuit.