How many sensors does a 1990 Cadillac Seville have?

Well, I have a Cadillac Seville 1990 4.5 fuel injection, and seeing as I already know my oxygen sensor is bad, I want to know how many sensors in total does my car have. If I'm going to replace one, I might as well replace them all. Thanks for your time people.|||It has numerous sensors, get the car to a shop asap.|||It depends. Dual exhaust? If so, 4 O虏 sensors, one fore and aft of each catalytic converter. And then of course you have the throttle position sensor, knock sensor, crank position sensor, and possibly others. Don't replace anything that isn't bad. O虏 sensors are not cheap.|||its got just one 02 senser.