Nissan Repair: Check Engine Light Soon, oxygen sensor, newer cars

Question
My check engine light soon is on.  I took it to a repair person....they said I needed the following:
Oxygen sensor
knock sensor
tune up
oil change
transmission service
raditor drain and fill

Can I get your opionion?

Answer
Hi Terry,

If you could please supply me with the actual code
number(s) and year and model I can tell you what needs to be done. Never change transmission fluid unless you do it every 24,000 miles, you can never change your engine oil enough, once a year on flushing the radiator, tune-up every 100,000 miles on newer cars. Depending on the code, it should only be one or the other on the sensors.