Bizzare problem

[RPM427]

O.K., I spent some quality time with my car over the 4-day weekend. Here is an update.

I was able to use my friends garage where he has a dyno and just about any scanner/tool you can think of.

the first thing I did was look at what was coming out of the exhaust. They hydrocarbons were off the chart, pegged at 2000 ppm. So that confrimed it was running rich.

I pulled a bunch of plugs and they didn't look too bad, a grey color, not too bad, but still rich.

I them put the car on the lift to get a better look at how the o2 sensor harness was routed. Not bad, but I pulled it out of the car and took a careful look at it. It seemed fine. I was expecting it to be burnt or broken.

I then checked evey sensor, BMAP, TPS, MAF, etc. Everything checked out O.K. , Except last time my FP was at 36, now it was at 30 I tapped the fuel press reg, and the pressure jumped around, so I ordered a new reg. But that coulndn't be all of the problem, the car was running slightly rich.

I then took a propane canister and injected some of it into the intake while tapped into the O2 sensors. As soon as I hit the valve, the graph jumped up and responded imedaitly to the inrichment. So the o2 sensors and harness were working fine.

I also knew that a vacum leak would cuase these problems but I couldn't find one. I got the idea to go around the engine with the propane tank and check again. Well guess what!, there was a small leak in the diaphram of the EGR valve. So I made a Plate out of aluminum and blocked it off. The car ran a lot better!, but not totally back to normal. After I get the regulator installed I hope it will be.

What does the deletion of the EGR valve do to drivability/performance?
Anyone got any ideas? Anyone ever have similar problems? Any input would be VERY helpful!