Does anyone know what GT-1 fault codes 28,29 and 201 are? I just got my car back from the shop. I paid $124 for an emission leak diagnostic pump and $294 for the labor and the SES light came back on 8 miles from the shop.

Here is what the bill says:
Customer reports SES light has come on.
GT-1 Test fault codes - code 28,29,201
Trace to faulty diagnostic pump in rear left wheelwell.
Replace Pump and reset codes.

Please help! I can't afford to blindly chase problems - college is expensive!

Thanks,
Beth