Reduced engine power
 

Have a Cadillac SRX 2007, used to run great, but suddenly today the message 'Reduced engine power" came on, out of nowhere. I had it with Cadillac.... Had been more in the shop than my other cars. Can somebody help me if it's worth spending $$$ again on this car or by a trusty other car ? Every time when it's 'fixed' it runs great, but that's than just for a while before other **** happens...