I think I'm having EGR issues myself. after driving for about 30 to 40 minutes on the freeway, the engine will start to bog down the more I open up the accelerator. The more gas I give it, the more it chokes. If I pull over and let it sit for about 5 to 10 minutes, it will run fine. Keep in mind I live in Texas and it has been in the triple digits lately. I'm sure the Texas heat has something to do with it. This is a 94 xl and it has been sitting for 5 years. I just got it up and running last week.