I have P1135, P0300, and P330 error codes. I'm getting the o2 and knock sensor replaced, and spark plugs. I was reading somewhere about part of the problem maybe the thermostat. Since I have no service records, I'm kinda guessing. Until I can save up some more and take it to Lexus to finish diagnosing it. However, overall the truck drives excellent. I'm just getting crappy gas mileage! Thanks for your insight!