93 Jimmy PROBLEM PLEASE HELP!

Ok, I have a 1993 GMC Jimmy s-15 4x4 4 door with the 4.3 liter.... no high output.... I am having problems with my vehicle. it usually starts find and drives pretty nice but every now and then it runs rough, when comming to idle speeds or stops it stalls unless you pop it into neutral and rev the motor. And sometimes when all this happens the Service Engine Soon light comes on, now the code it spits out is an EGR Problem, So i figured the vehicle is 10 years old and has 150,000 miles on it, so hey its gonna go out eventually, so i replaced it......200 dollars later, the new egr is on and the vehicle runs well for a few days, then it all starts to happen again, even the service engine soon light is on. I took the new EGR off and it was dirty as heck inside with carbon, so i cleaned it out and placed it back on, the next day same thing and its still doing all this, actually its slightly worse now. So now the dilemma, am i 100 percent sure its a carbon buildup, just about....All the mechanics i go to want 300 bucks to take off the Intake Manifold off and clean out everything to rid the carbon, thats if it is a carbon buildup. I dont have 300 bucks, nor the mechanical time and knowledge and patience to do it. A family member of mine told me he had the same problem in his 89 iroc camaro and filled it up twice with 110 racing octane fuel and romped on it a little bit and it cleaned it out. What would be my best bet, and do you guys have any opinoins. Thanks

Mike

http://www.automotiveforums.com/vbulletin/showthread.php?t=136982

Click on that link and see if this will help.
There is a link for a company that makes a screened EGR gasket that might solve your problem.

Just went through same problem tried all other avenues but it was carbon problem it was worth the hassle it runs better than ever!!!