Hello, I have a gen 2 prius w/ 300,000 miles on it. Car runs beautifully. I was due for an emissions test but got a check engine light. We only got the catalytic converter replaced w/ an aftermarket one. The check engine light went away, it has not appeared in over 2 months. However, using an OBD2 scanner my car isnt ready for emissions. I have driving the car way over 5K miles since changing the converter. People have mentioned a drive cycle but I've literally driven the car so much by now. Evaporative system is reported as : not ready Oxygen sensor: not ready what do I do about this?
You need to get the car properly scanned because something is keeping the emissions system from completing it's checks - most likely the aftermarket CAT. Any Prius aware scanner should be able to tell you what's hanging-up the diagnostic system - It's stuck in a retry/recheck cycle.
You need to complete an emission test cycle to trip another emission code. As I stated earlier, it's stuck in a retest cycle - a good scanner will tell you which test it's stuck on. I'm just guessing it's that aftermarket CAT. What codes were you getting BEFORE you replaced the CAT?
did you check the upstream and downstream sensors for proper function before replacing the CAT; since your getting O2 sensor not ready. Are the sensors plugged in and fully operational? the proper scan tool will tell you this and give you readouts. ditto with the evap 'not ready'. valve not toggling, high or low leak rate.
