Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 3 of 3 Posts

· Banned
2004 gmc
26,436 Posts
Without a scan tool that can read out the O2 readings to look at the numbers, it is difficult to tell. The shop manual says to look at the measurements, then replace the sensor, then replace the cat. Do you have a mechanic to get help from?
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.