Sensors are grouped by the system they feed, because that is how a fault code leads you to them. A P0133 points into oxygen sensors, a C0035 into wheel speed, and a U0121 into the ABS module rather than the sensor itself — the product pages keep the OEM interchange number visible so you can confirm the circuit before spending money.
Most sensor failures are connector problems, not element problems. Check the pin count and the keyed shape in the photos against the harness plug on the car; a sensor that physically fits but reads the wrong resistance will set a code again within one drive cycle.
