Pulled fan rely, still grounded.
didnt have a rely for the secondary fan. im guessing thats a z28 thing.

disconnected purge wire harness, still grounded.

yes key is always on,
im testing wire D, for ground.
so??

thinking about testing the fuel pressure tomorrow.
anymore ideas?

Did I mention the SES light comes on while slowing down
maybe thats a clue

Well I fixed the EGR issue. It ended up being the upper intake manifold. I replaced that and it hasn't thrown the code since. But that didn't stop the sputtering and backfiring in the intake and horrid fuel mileage. I took the car to GM today for a diagnosis and It turns out that I have a temp sensor reading -38 degrees, causing the car to run rich. Nice eh? Well I have a new sensor ordered and I'll update when I get it installed!

found this on a diffrent thread.
i think i have the same problem with the upper intake.