Westers Garage has been doing programing for me for some time. Have an 89 K1500 with 7747 computer, used to run Edelbrocks TBI to MPFI conversion system but changed to Vortec heads and Edelbrocks Hi Flow tuned port setup, TB flows 785cfm. This is an older problem for me even with the original Edelbrock tune, the check engine light comes on in cruise on the highway- code 32 which seems to be a common problem. I have been told that the GM EGR valve is a 'balanced' valve and since my exhaust works so good its screwing up the valve with not enough back pressure. I looked into part numbers and the '91 vette EGR is different than the Camaro EGR valve, I was thinking that since the vette exhaust is so much better than the Camaro it may work for me- also the vette plumbing is similar to mine in that EGR tube comes off the header. The code was shut down so the light wouldn't come on, but it seemed to impede EGR function- right now under heavy throttle there is pinging, with the code off pinging was present even at moderate throttle. In the past I used 94oct all the time and now am using 89oct- so if the tuning wasn't great the 94oct is now no longer a crutch. My mechanic suggested that I get a 'universal EGR' with the disc orifaces and experiment with the disc's- I really don't want to tear down the manifold multiple times. I know there is alot of experiance out there- hope you can help me out. davefarr@telus.net