Cadillac Repair: Clearing Readiness Codes, digital speedometer, climate control

Question
I have a 1998 Seville that I had to have a leaking headgasket and intake gasket repaired to prevent overheating. Now the car runs good but has 3 readiness codes I have not been able to clear. I need to get them cleared to get the car inspected. The readiness codes are Catalyst, Evaporative System and O2 Sensor Heater all reading not ready. I have ran the car over 80 miles for the computer memory to try to reset these codes with no luck. I have also checked all fuses and they are all good. Got a ticket for driving today with out current inspection trying to put some miles on the car for memory to clear codes. What should I do next. Thanks in advance for any assistance..

Answer
You will be using your drivers side climate control panel ONLY if you have a DIGITAL speedometer.

1. Turn ignition switch ON. Do NOT start the engine.

2. Simultaneously push and hold the OFF and WARMER (fan up) buttons on the climate control panel for 3 seconds and release them.

3.On the fuel data display you will see the CODES display and after EACH code you will see the word History or Current.

4. Turn ignition OFF.

Let me know what codes you get and which ones are History and which ones are Current.