THis is very common! The mass air flow sensor goes bad all the time and will cause all sorts of problems. THe mass air flow sensor has been known to cause converter codes and air fuel sensor codes as well, It is easy to get tricked into replacing these parts as the root cause is the mass air flow sensor.
I would replace the mass air flow sensor regardless. Get one from the delearhip and put it on yourself.... it is not hard.
I am not mechanically inclined. What do you think would be a reasoanble charge for parts and labor. I was quoted $453 by the dealer.
THat does sound right... a bit high... but reasonable.
How important is it to get the part from Lexus directly vs reconditioned part? If I take it to a local shop, is it necessary for them to do their own diagnostic?
It is very important to get a an O. E. part on your vehicle. If the dealership already diagnosed it, then you do not need to pay again for another diagnoses. You can always have the local auto parts store just put the part on for you.
I hope this helps. You can always accept my answer now, and repost back again later on if you have any more questions. If you want to discuss it some more just hit "reply", it's free to do so otherwise don't forget to hit "accept" and leave positive feedback if you found my answer helpful.
Thanks for your help. One last question: What is an O.E. part?
O. E. means original equitment
Did you have any further questions?
No thanks again.