Red means action
A red oil, coolant or brake light usually indicates a safe stop and engine shutdown. Continuing can cause expensive damage.
Orange engine light
Steady lighting often allows careful driving, flashing can signal ignition failure. If the car jerks or loses power, do not continue driving.
Diagnosis instead of estimation
A fault code is a start, not a finished diagnosis. It is properly compared with live data and measurements so that functional parts are not changed unnecessarily.
Every vehicle and fault is different. This article provides general guidance; an inspection of the specific vehicle determines the correct procedure.