Fuel Injector problems of the 2004 Cadillac SRX

My 2004 Cadillac Srx has 98000 miles on it. The service stability system light comes on after driving for 20 minutes, each time I start the car. I clear the system and just drive. The car shakes while driving a bit and does pull to the right. I am not experiencing some of the problems many others are facing with this same warning, but feel I too will soon, it is getting worse. I also was forced to put in 89 octane gas at a station that didnt have super, I had a low fuel light. After 20 minutes of driving stability light came on along with check engine. I cancelled my trip and drove to my mechanic. He stated there was a misfire which may be from lower grade gas but after a fill up of super and a full day of driving check engine light is flashing. Bringing it back to get serviced I was told there was no misfire, clogged injectors norfaulty plugs. The problem was with the ecu. These cars sense a problem and "shut off" the problematic fule injector. Well mine is not problematic but the computer says it is!!! now what buy a new ecu!!! 149. 00 for the diagnostic and over 500. 00 for the ecu not including labor, I'm looking at a grand to fix the problem, if this is the problem!!! I really love the style and look of this car, but all the extra crap is overkill. There needs to be a recall for the stability system quick, we are going to have a Toyota situation on our hands.