engine light on amber

[dti owner]

when i bought my vectra it was fine and then the engine light came on and has been on for the last 2 months, i have no problems that i can see or hear. i am trying to get my obd2 software to work so that i can use my diagnostic software. i did read that if it goes red then its bad, if it stays on will it get worse whatever the issue is?

[roswell]

engine normaly = emissions system
emission system = egr valve

but its not a rule just a pointer