Today, my 1991 Camaro Z28, 5.0L V8 spit out four codes.

33
42
43
54

CAn someone help me out what some of these codes mean?

 

33. High voltage (low vacuum) at mass air flow sensor (or MAP sensor)

42. Fault at electronic spark timing circuit OR
Fault at direct ignition system OR
Fault at fuel cutoff relay circuit

43. Low voltage at electronic spark timing circuit

54. Low voltage at fuel pump OR
Low voltage at Fuel pump relay OR
Output failure at quad driver module



Good luck!