I just recently got some 20's on my car after having the stock sport 18" rims. Both rims have tpms sensors on them but now after having switched to the 20's the tire pressure light always comes on. Is this normal or should I get it checked out?

 

you have to get them reprogrammed at infiniti i believe

 

^^^+1, if these are different sensors that came with the car the dealer will have to reprogram them.
Every time you switch to different sensors this must be done.

That is why a lot of us don't bother with sensors in our summer wheels.