98 Z24 is idling rough

I just bought an automatic 98 z24 caviler that is idling rough. When I am driving around everything seems to be fine. It only seems to be when I'm idling. I just put new spark plugs in it and nothing seemed to change. I thought about it being a vacuum leak but I can't seem to find one.

did you try spraying carb cleaner around the vac lines to see if the idle changed? the first place to check would be the vac line going to the MAP sensor (pull off the intake box right on top of the front side of the engine and you will see a small square sensor on the front side of the throttle body), my 97 z24 idled rough and would stall at stop signs until I found a rotten vac line on the MAP sensor. Give it a try and let us know what happens.

Thanks for the tip Jacfourteen, I went and got some carb cleaner and sprayed it around the throttle body nothing, by all vacuum lines nothing. Then I thought it might be my manifold gasket so I started spraying around there, and I found it the fuel injector was leaking air. The o-ring was sticking out. So I replaced all of them and the problem is gone. Thanks

Glad to hear that you got it fixed and that I helped out.