Cutlass Supreme S questions.

The car

1992 Cutlass Supreme S, 3.1 Liter, automatic, 140 000kms, I don't know too much about the car yet i haven't looked at it much. I'm used to working on older pre-computer cars.

The car has an idle problem, it will wander from almost stalling to normal idle.
I first suspected a vaccum leak when he described it to me. Anything else I should look for? could be a plugged CAT, oxygen sensor, ignition components? I have a gm code reader for that year so I will be pulling the codes,

I need to change the spark plugs/wires, is it possible without rotating the Engine forward by unbolting the dog bones?

i was supposed to work on the brakes on this car yesterday but we found out that three of the wheel have locking lug nuts and get this with three different keys It's a repoed car so we don't hve the keys, were going to crack those later today and get on with the brakes

Thanks for any advice you can provide with the lack of details.

 

Remove the intake snorkal. Have someone else hold the throttle wide open from inside the car. Now take a can of carb cleaner and an old toothbrush and clean the backside of the throttle plate and the surrounding housing. That should help a lot.

 

The suggestion before mine is great, I did this as well, but there are 2 vacuum lines and they are white or clear in color and mine was doing the same thing and one of the vac lines LOOKED good, but when I went to take it apart it had a crack in it (probably for a long time) and I never would have noticed. pull on off at a time and put your finger over the hole and see if things improve. good luck