Wheres the emission sensor switch located ? on 1991 Chevrolet Cavalier

What does the emission sensor switch look like? Wont start unless the gas pedal is held down and sputters, has rough idle

Asked by for the 1991 Chevrolet Cavalier
Take it to a shop there in Potwin, you don't have a clue.
Put you're right information in for your city and state would be helpful. There are several sensors that work for the emissions but none are called specifically an emissions sensor. If you have no clue How can we help
1 more answer , 2 more comments
Emission sensor switch , is located on a printed circuit board inside the PCM , and is triggered on when various inputs from other sensors are 'out of range' or it is determined that they have a performance problem. I have found 'GREEN JELLY' brand throttle plate cleaner and lube , helps with avoiding some false inputs , from throttle position sensor , at times.
Thank you , thank you , very much.