which is different than all others posted:Check all diagnostic functions as follows:
• The test must take place on the road with little traffic where it is possible to drive slowly and stop at the side of the road.
• For all diagnostics to be carried out, the engine coolant temperature must be between -7° C and 35° C when the engine is started, or 19.4 - 95° F before the test
• Ensure that there are no diagnostic trouble codes stored in the engine control module (ECM) before carrying out verification.
Schedule:
1. Switch the ignition on for five seconds.
2. Switch off the air conditioning A/C
3. Start engine. Allow the engine to idle for 10 to 20 seconds.
4. Accelerate gently to 70 – 80 KM/H, 43 - 50 MPH
5. Drive at a steady throttle opening at 70 - 80 KM/H or 43 - 50 MPH for 15 minutes.
6. Engine brake down to 30 KM/H or 18 MPH, fully release accelerator pedal.
7. Stop the car. Leave the engine running.
8. Idle the engine for one minute.
9. Accelerate to 70 - 80 KM/H or 43 - 50 MPH, for manual transmissions, first gear up to 40 KM/H in five seconds.
10. Switch on air conditioning A/C.
11. Drive at a steady throttle opening at 70 - 80 KM/H, 43 - 50 MPH for 5 minutes.
12. Stop the car. Leave the engine running. Read off the data.
Especially step 10 is different than anything else posted online and made all the difference. Tried all the other variations and before this the measurements for catalyst and oxygen sensor could not be read.