My Sunfire's speedometer and transmission is acting up. At times the speedometer won't work or if it does it will fluctuate up and down. When either of these things happen sometimes the transmission will have problems shifting. We replaced the transmission output speed sensor. (bought from autozone) which has fixed the problem in the past. The check engine light went off when we replaced it. Could it be a bad sensor that we purchased? What are my other options?

Replace the Vehicle Speed Sensor (VSS).

OK we will try that again and let you know. Maybe we just bought a bad sensor.

Replace the Vehicle Speed Sensor (VSS).

OK we will try that again maybe we just bought a bad sensor.

The Transmission Speed Sensor and the VSS are two different sensors.