Toyota Repair: rx 300 vsc/check engine light, trouble code, code numbers

Question
I was driving on the freeway and my car started "sputtering", the vsc and check engine light came on.  Any ideas?  I just had a major tune up and timing belt

Answer
I would need to know the trouble code numbers in the computer to help, can you have the codes retreived? Most autoparts chain stores such as autozone, kragen etc will get the codes for you at no charge. Or you could take it back to the place that did those repairs and ask them to explain why these lights came on after they worked on it.