Toyota Repair: check engine light, air fuel ratio, charcoal canister

Question
I have a 2002 Toyota Sienna with 63,000 miles. I have had all routine maintenance done on time and I just did the 60,000 mile service. My check engine light came on and I took it to the Toyota dealer. They ran the diagnostic on it and said I needed a charcoal canister and a air fuel ratio sensor. All total parts and labor this will set me back about $750. Question is do I have a valid complaint about having to spend this amount of money on a vehicle that only has 63,0000 miles. Just what is the average life expectancy of a charcoal cannister and a air fuel ratio sensor? Knowing next to nothing about vehicles, I really appreciate your answering my questions.

Thanks.
Trish


Answer
Without knowing the actual diagnostic trouble code numbers I can't be very specific in my reply but I can tell you that the A/F ratio sensors are a common failure item, not so much the charcoal canister, I'm not saying it doesn't need it just that it's not a common failure, if you could let me know what trouble codes are that they found I can be a lot more specific.