Engine Codes - Help

[SurJones]

Popped a engine light on my 02 Envoy. Can you guys help with what exactly these are. thanks!

B0237 - Rear Wheel Speed Signal Erratic

B0267 - Pump Motor Circuit Open

B0281 - Stop Lamp Switch Circuit

P0420 - Catalyst System Efficiency Below Threshold Bank 1

 

[The_Roadie]

Recommend a short search here and at trailvoy for previous discussions on those codes. The first two relate to the ABS system. Have you tried out the ABS functionality on sand or gravel lately to see if it works? Is the ABS light on?

The third one relates to the brake lights. Do they work reliably?

Last one could be a bad catalytic converter. Get a scan tool on it that can look at O2 sensor data and see if the post-cat (downstream) sensor data is varying or steady. It should be steady.