Hi. I recently Pigtailed off an existing outlet that was 14g wire and ran to a new outlet that I installed with 12 gauge wire. Any problem with this? The new outlet is for a cable box and DVD player so there will not be much draw

No problem.

The simple answer is yes, but with clarifications.

!4 AWG and 12 AWG refer to the size of the wire, not the recepctales. A 14 AWG cable can carry 15 Amps. So you would use a 15 amp receptable. A 12 AWG cable can carry 20 amps and you should use a 20 amp receptacable for this circuit.

Because you have a multi-outlet branch circuit, you must limit the load to no more than 12 amps. This includes the new receptacle.

What you cannot do is to put a 20 breaker on the circuit, doing so may cause a fire.