2001 blazer - Original issue was a #6 misfire. swapped out the spider & replaced the temp sensor on the driver's side at the same time. Reset the codes. It's been over 600 miles and codes are not ready. Did the driving cycle one time. seemed OK but they threw up the #6 miss again. Also had a map sensor issue that has gone away. Secondary air system code showed up and went away. This seems to be a common issue. How to solve it is my question. Should I spend the day doing the driving cycle over and over? I cannot leave my driveway and run 55 right away. It's about 3 miles to the highway. Is a delay between the steps in the driving cycle OK? There is an issue with the heater but that appears to be the door controls. Temperature gets up to the norm it has been at for years. Help, please!!

 

I did the driving cycle again today. Now, all the sensors are not ready along with several other hard codes. Any ideas? Could this be the computer itself? How can I check it?