Colorado tests emissions, and a failure is usually a symptom of something the car has been reporting for a while.
A failed test is not one fault. It can be sensors, the catalytic converter, a leak in the evaporative system, or an engine problem the test simply found first. The test tells you that it failed. It does not tell you why.
Modern cars run on what their sensors report. A sensor reading wrong is not always a broken sensor: sometimes it is correctly reporting a real problem somewhere else. Telling those two apart is the actual job.
A car that will not start is a battery, a starter, an alternator or a connection. They are quick to tell apart with a test, and expensive to guess at with parts.
If it has been hit and it also needs mechanical work, it does not need to go anywhere else.