Previously, my "maintenance req'd" light would be lit all the time, but I assumed that this was due to the fact that I'm running a high-flow cat with my obd2 ecu, so it was the secondary 02 sensor setting it off.
Today, I took off the negative connection on my battery because I had to move it, and after reconnecting it, the maintenance req'd light is off, but the check engine light is on. Whats the story here? Should I reset the ecu again, and hope the light goes off? Idle is fine, haven't driven it yet but there doesn't seem to be anything out of the ordinary. If anything, shouldn't the "maintenance req'd" light have stay lit, instead of it being the "check engine" light?

 

check the code and see which one it is.

 

An easier way to turn off the maint. reg. light is using the button that turns if off. Its under the driver side dash facing towards your feet. turn the car to the "on" position I think and then hold it till the light goes off. It will only come on ever xxxx amount of miles. It had nothing to do with your cat.

 

very useful!