98 windstar SEL lamp HELP!!

98 Windstar 128,000. Replaced front IMRC from Rock Auto (found that from here thanks) replaced intake gaskets @ 120,000 with all recomended parts per this forum, now problem is when van idles for a short period the SEL lamp will come on again, pulled the codes and it said that the codes for the IMRC was the problem again. How? I am pulling my hair out on this one, someone pls help..need to get it inspected!

OK everybody, I pulled the codes tonight and I got the dreaded P1538 code again! I have searched this code from the start and found the info about the IMRC stuff. replaced as mentioned the closest to the rad. quite a while back (before the intake gasket repair) I checked to see about the pulling off the vac. line on one and checking, both seem to be working fine...what is the deal? After it idles for a while the light will come on and bring up that stupid code. It might take a while but it keeps coming back, please help..any ideas?? Nobody seems to have this occur after parts replacement or am I missing something?