Engine light stays on

Hi, I am looking to buy a car next week it is the car listed above. the guy said they put three sensors in the car already and the light is still on the next step they are going to change the computer my question is to you ,since this car has that 3.6 llt aluminum engine block I presume from the Cadillac CTS. do you think it is the engine or the timing chain? I read that not all of the Suzuki's had these defective engines, just the ones that were manufactured in Arizona, California, Nevada and Texas .I do not have a lot of money I have a limited income, and I really cannot afford to get stuck with a lemon and I definitely cannot afford car payments. please I need help. I really do not know what to do. Buy it if they can fix it or continue searching? Thanks