Oldsmobile/Buick Repair: Diagnostics, circuit failure, cam sensor

Question
I have an oldsmobile year 89 model ninety-eight royale

Recently had a diagnostic check error codes 41 which is beleived to be cam preference signal, also error code 26 which i have had different people tell me thats the quad drive module, DIS module, or ignition control module which one is it i need to know so i can get the part Autozone never heard of quad or DIS which usally means distributor i called oldsmobile and they said ingition control which one is it the last error code was 63 which is egr valve solenoid is that the egr valve i need explanation because is the valve the whole component or something all to different .  Sholud i use autozone parts which are somewhat cheaper and also they said i might need to get the coils what are the coils  please help me sort this out


Answer
Yes, you can use Autozone parts.

41=cam sensor circuit failure.

26= quad driver module.

63= small EGR fault.

I have no idea what COILS they are referring to.

The FIRST thing I would do is to have someone erase the codes and then see if any of these codes come back.