85 Iroc running rich

Can anyone help me with a question that I have on an 85 Iroc? It has a Tuned Port 305, rebuilt 20,000 miles ago. It has T-tops, but I don't ever take them out anymore because the exhaust smells. It smelled
before the engine was rebuilt as well, but was not the reason for the rebuild. It is choking me out. I just drive it around town. When I do get on the freeway, and am driving at a constant speed for 10-15 minutes, the check engine light comes on. It gives me an EGR error. This is the second EGR valve that I have had in it, and I still get the error. The second EGR was out of an 86 parts car that I had. Could it be another bad EGR, or is there something else that is causing it to run rich? The timing was set by a local tune up shop. When I tried to time it, the timing marks were off by about 90 degrees. Also, the cat seems to have been hollowed out before I got the car. I have planned on replacing it with a high flow. Would that contribute to the problem? Could my fuel pressure be too high or too low? It has the factory non adjustable pressure regulator and a fuel pump that is at least 4 years old. Also, the computer was replaced with a new factory one. It has K&N filters and a flowmaster. Any help is appreciated. I am trying to find the problem without spending every cent I have. My wife won't drive in the Iroc with me anymore, we always have to take her jeep. This is killing me.
Thanks, Will
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It's extremely common that the egr passages will be clogged. You'll need to remove the plenum and the runners and clean those passages out then try to clean out the EGR passage in the intake. It'd be best if you could take the intake off but you can do it without removing the intake, it's just more time consuming and harder to do but it's do-able.
You might run some BG cleaner in it.. It's supposed to dissolve or soften up any crap that's in the EGR passages but if it's clogged, it won't really help.
You should be able to check your fuel pressure but it would be unlikely that it's *too* high or the engine wouldn't run very well. If the diaphram in the regulator is punctured, then raw gas is getting sucked into the vacuum system which could cause problems. The fuel pressure regulator just helps to maintain constant fuel pressure across the injector. If fuel pressure is higher at some points, the computer will compensate by reducing or increasing the injector duration.
The best thing to do at this point is to go and get the exhaust checked. If you're smelling raw gas, then you should already have a good idea but if it's just a smell, you need to figure out what you're smelling so you can limit the possibilities.
-Bruce
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snipped-for-privacy@swspambegonebell.net says...

I would imagine TPI cars are set up the same as carbed cars but there should also be a thermal vacuum switch and electric EGR solenoid too. You might want to check those too.
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