Redrover failed its NC inspection yesterday, due to three systems reporting Not Completed - Catalyst, O2 Sensor and Evaporative System. No fault codes, they were just not ready, meaning not enough drive cycles had been completed. What surprised me about this is that it's been a long, long time since I had any problem with the O2s/Catalyst system, and I've never had a problem or any fault codes related to the evaporative emissions system. Nor has the battery been disconnected in many, many months.

The only thing I can figure out is that I recently cleared the 1590 Rough Road Signal code associated with The Three Amigos, and that may have reset the "counter" for the systems that failed. Does that make sense to you guys? Thanks.

 

Yep clearing the codes will reset the monitors. I just dealt with getting my truck smogged in Cali. Drove about 50 miles and the monitors finally set. The drive cycles are in RAVE. Doing street/highway driving first, then freeway driving seemed to work best for me. Not sure about NC, but in Cali the EVAP monitor doesn't need to ready, but the other 3 do. I think the EVAP monitor only sets with less than quarter tank and left alone overnight.

 

After driving mine around for about 300 miles I was able to get mine smogged in Calif. I tried at 100 & 200 miles and the evap counter finally reset...

 

Usually the o2 and cat set pretty quickly. Evap takes longer to meet requirements. You can have 1 not ready and still pass.

 

Mine failed I did a drive cycle that I found on a Mercedes forum for both my cars I was able to get everyone one to reset in 15 miles search for it online

 

I had a disconnected battery and it took 200 miles to get the EVAP green again. The others got ready with way less miles. The ECU wants to see certain drive cycles (acceleration, speed, duration, temps) and this can take very long with normal driving, in worst case forever. In the workshop manual (pp. 18-2-58) there are drive cycles described which accelerate this process.

 

In NC if the car is between 96-99 you can have 2 not ready, 99 and newer only one. Your o2 monitor will be ready first. Drive it around for a few days the head back over to get reinspected. Any time you clear a code it will reset your monitors.