I can't get my 2002 Highlander drive cycle to complete. The CAT and EVAP cycle simply refuse to complete. This started with the OBDII throwing a bad knock sensor code. I replaced both sensors and the harness with after market parts and cleared codes. But after 500 miles the cycles still wouldn't complete. Then an 02 sensor went bad. I replaced it with genuine Toyota parts. After 800 miles still the two cycle wouldn't complete. I took it to a shop and they said to replace the EVAP solenoid purge valve. I paid the shop to replace it. After 600 miles the two cycles still wouldn't complete and knock sensor error code came back. I paid a shop to replace both sensors and the harness with genuine Toyota parts. I drove it another 600 miles and still EVAP and CAT won't complete their cycle. The shop, which is an expensive and reputable shop, threw their hands up and said take it to the dealer they have no idea what to do. Anyone have any knowledge on how to fix this? I have tried multiple different guides that say how to drive to complete the cycles and none have worked. I would be grateful for any suggestions. I am thinking it needs a new catalytic converter but I don't want to spend that money if I don't have to. Thanks everyone.