have a egr code for P1406...

replaced egr with new and check to make sure egr ports were not clogged....

hooked up my snap on scanner,
run for about 2 mins at idle,
then i can accel to above 1500 rpm and the egr will show to be at about 18% with a desired at 0%....

even upon returning to idle it will show to be around 18% with a desired of 0%..

the egr voltage will go up from .66 when the engine is accel above 1500, but will return to .66 upon engine returning to idle but the egr will show to be at around 18%......

also after it sets and idles this way for a couple mins it will start to accel on its own, the iac steps go to 195 and the engine revs above 1700. maf show to go from < 6 gps to > 18 gps ( iac open at 195).....

all other data appears normal...

any help or ideas would be very helpful...

thanks in advance,

mike

Take off th eEGR tube that gose from the EGR valve to the LIM. Hold it up to the light, it may be cracked.

the tube has no leaks that i can find. i think the problem is in the electrical somewhere, not a mechanical problem.....

I would think that a cracked tube or a vacuum leak would explain a high idle all the time. In this case it is more random, not all the time.