92 s-10 loosing power
 

I have a 92 S-10 blazer 4.3 4WD that is loosing power. Have changed the ignition module, full tune up, fuel filter and had spider replaced. Distributor has been checked and it is fine as well. It runs great until the check engine light comes on. Once the light comes on it looses power no matter how hard I press on gas pedal. If you shut the truck off and restart it, it runs fine again.

Do you know what code comes up when the CEL is on?

I have an old school tester and it was 43