Failure to Prepare for Heated Catalyst (HCAT) in SMOG Test: Drive Cycle
Posted: Mon Jul 06, 2026 5:29 pm
This is absolutely infuriating me. To get my 2017 RR Sport TD6 through California's emissions testing, I need to put it through its paces. Except for one, I have successfully prepared all of the monitors. The Human CAT Scanner.
Do you have a tried-and-true method for fixing this?
Despite my best efforts, I still don't understand this. I have tried all four of the drive cycles (A–D) that are provided on the forums, but this one still won't test. To try and figure out this last monitor, I drove 200 miles today with 3/4 tank of petrol and no DTCs.
The Heater, as far as I can tell, improves emissions by warming up the CATs during cold start. That being the case, I suppose I should do this as a fresh start. The "not ready" message persists despite my attempts to use the air conditioner and rear defroster cold start procedures.
I have an Autel; are there any diagnostic procedures I can follow to verify the heater is functioning properly?
Would greatly appreciate any assistance!
Thank you ahead of time
Do you have a tried-and-true method for fixing this?
Despite my best efforts, I still don't understand this. I have tried all four of the drive cycles (A–D) that are provided on the forums, but this one still won't test. To try and figure out this last monitor, I drove 200 miles today with 3/4 tank of petrol and no DTCs.
The Heater, as far as I can tell, improves emissions by warming up the CATs during cold start. That being the case, I suppose I should do this as a fresh start. The "not ready" message persists despite my attempts to use the air conditioner and rear defroster cold start procedures.
I have an Autel; are there any diagnostic procedures I can follow to verify the heater is functioning properly?
Would greatly appreciate any assistance!
Thank you ahead of time