GM Repair Questions? Ask a Mechanic for Answers ASAP
The P0155 code is for an O2 sensor that is unresponsive. This code will not set until the engine is running, so it is not the cause of the no start condition. P0442 and P0446 codes are for leaks in the evaporative emisssion system, possibly a loose gas cap, again not the cause of the no start. I would suggest clearing these codes and see if they reappear after the engine has been run.
I know you said you have good spark, try removing the distributor cap and inspect the inside of the cap for moisture and corrosion buildup. This is somewhat common on these engines. Let me know what you find.