s10 4.3 misfire and lean
 

Ok, I have a 1999 s10 blazer with a 4.3l v6. This week, I started getting a check engine light for egr valve. One day it wouldn't start until I let it sit for a while. When I was cranking it over it would fire on one cylinder, and smelled like fuel. This would be about the fourth or fifth time in a year it has done that. (Flooding?) Anyways, friday I pulled a code for misfire on cylinder 3, and saturday I pulled codes for misfires on 3 and 6 on the way to work. On the way home I pulled a multuple misfire code as well as low voltage on both o2 sensors. I tried pulling spark plugs but they are locked in and I'm going to leave them until I have time monday. Today when I ran it, I could hear it misfiring at idle although it didn't give a code until I pulled up a hill. Under no load, when you hit the gas it misfires badly and then smooths out at higher rpm. When I removed the air intake cap from the throttle body it just about died. Under load I can hear it pinging when I step on it, usually out of the left bank. Any ideas? Timing, spark or fuel? I'm thinking it could be the fuel pressure regulator, but I don't have the gauge to check pressure.
Thanks for any and all help ot advice
Justin