runs awesome went to smog n codes 420,misfire cyl 1,cam timing sensor?

What is your question?

Car runs awesome not a hiccup with 200000miles taken to dealer for all services. But smog tec tells me it's not worth fixing n I need to sell it,n check engine light was disabled somehow? I reset codes n only came up with code 420, Can't believe car is not worth fixing! Runs awesome super clean...