Question about CELs with the EQT tunes. The car has a catted downpipe and was running EQT 2.51 with no CEL. After upgrading to the 2.63 tune, a CEL has popped up for P0420. It's my undertanding after searching that newer tunes are forbidden from turning off the CEL so there was surely one present with the 2.51 tune but it was being supressed. Going forward, which of the following makes the most sense:
1. Go back to 2.51 tune
2. Go back to 2.51 tune and unplug the second O2 sensor using the CJM plug spacer since there may be creep
3. Stay with 2.63 tune and install an O2 sensor spacer to get rid of the CEL
4. Stay with 2.63 tune, install an O2 sensor spacer and unplug the second O2 sensor to prevent creep
5. Stay with 2.63 tune and ignore the light