tire replacement - tire pressure sensors

I was told that the valve stem can't be replaced on tires for cars that have tire pressure sensors.
Why is that?  What do I say to the tire shop before changing my tires?
thanks



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ORIGINAL: skippyDTS

I was told that the valve stem can't be replaced on tires for cars that have tire pressure sensors.
Why is that?  What do I say to the tire shop before changing my tires?
thanks

That you will get a 2nd opinion.
What they should NOT do,  is remove the pressure sensors and chuck them.

OK .. I gotta ask .. what do you have and who said that?

I don't have tires yet, but WalMart has good prices.   Is WalMart a mistake for tire replacement?
My father had trouble because they did something with the valve stems or something.  I didn't pay close enough attention.
Are the sensors part of the valve stems?
I guess I could look it up myself