Mitsubishi Repair: 2002 Mits. Galant with service engine light on, upper radiator hose, service engine soon light

Question
I recently had my upper radiator hose replaced because it was cracked.  When I picked up the car, the service engine soon light was on and won't go off.  The repair shop put the car on the OSB II box or whatever it was called to check why the light was on.  3 codes came up: P0132, P0134 and P0135.  Is there any correlation between these coming up and the radiator hose being replaced?  Is it very crucial to have these things repaired ASAP?  And, do you have any idea of the cost involved?  Thanks for your time.

Answer
You didn't tell me which engine, so I can't tell you which O2 sensor, but you have codes for #1 O2 sensor. I would follow the harness from the front O2 sensor(s if V6) to their connectors and make sure they didn't unplug it for access. If it's like my Eclipse, it hides right under the t-stat housing and may have been disconnected to access the clamp on the upper hose at the t-stat housing????