My throttle works fine but my steering servo is stuck to the left. Any ideas?

Bad potentiometer or broken gear

Try a different servo of swap channels TH<>ST

Definitely was the servo and esc setting. Thank you.

Probably nothing wrong with RX & TX, its the servo. You can replace servo or upgrade to better servo. Spektrum RTR TX & RX are junk anyway. Invest to Futaba or Sanwa more expensive, they have an EPA(END POINT ADJUSTMENT) so the servo is not overloaded.
(

Thanks for the info. The SLT3 does have an EPA adjustment too.