I had my mechanic run the code which is causing the check engine light on my 94 olds 98. It turns out it could be three things but it comes on periodically and sometimes I drive the car for 10 mins and it comes on and sometimes I drive it for 45 mins and it doesn't. He told me the current code was the EGR Position Circuit and past codes were a Misfire (Not Specific) and the TPS Sensor. The car probably needs a tune up and I know where the TPS sensor is so that should be an easy change if need be. As for the EGR Pos. Circuit, I removed the EGR valve and inspected it. The valve itself moves freely and there was no build up of carbon in the motor or the valve. Any other ideas what the EGR Position Circuit can be?

https://www.gmforum.com/trouble-shoo...sensor-279319/
you could see if you are getting proper voltage to both tps and egr. another thing to look for with egr faults on 3800'* is cracked serated metal pipe to lower intake