Valve lash is not adjustable on the 2.2L.Here are the R&R intructions:
See Figures 1 through 5
Remove the rocker arm cover from the cylinder head.
Unfasten the rocker arm retaining nut, then remove the arm and ball. If necessary, withdraw the pushrod form the cylinder head.
Valve train components which are to be reused MUST be installed in their original positions. If removed, be sure to tag or arrange all rocker arms and pushrods to assure proper installation.
Fig. 1: Unfasten the rocker arm retaining nut. A long extension may be needed to avoid hitting your hand on any of the surrounding components
Fig. 2: Once the nut is loosened, remove it from the rocker arm stud
Fig. 3: Remove the rocker ball and washer (which should be inside the rocker arm). Be careful not to loose the ball
Fig. 4: If necessary, remove the pushrod
Fig. 5: Use a torque wrench to tighten the rocker arm nuts to specification
Inspect the rocker arms, balls and pushrods for damage or wear and replace, as necessary:
Check the rocker arms, balls and their mating surfaces. Make sure the surfaces are smooth and free from scoring or other damage.
Check the rocker arm areas that contact the valve stems and the sockets that contact the pushrods, make sure these areas are smooth and free of both damage and wear.
Make sure the pushrods are not bent; this can be determined by rolling them on a flat surface. Check the ends of the pushrods for scoring or roughness
Inspect the rocker arm bolts for thread damage. Check the rocker arm bolts in the shoulder area for contact damage with the rocker arm.
If removed, install the pushrods making sure they are seated within the lifters.
If installing new rocker arms and balls, coat the friction surfaces using Dri-Slide Molykote® or an equivalent pre-lube.
When tightening the rocker arm retainers, make sure the lifter for that valve is resting on the base circle of the camshaft NOT on the lobe. DO NOT overtighten the retainers.
Install the rocker arms and ball, then tighten the retaining nuts to 22 ft. lbs. (30 Nm) on 1994-97 models and 19 ft. lbs. (25 Nm) on 1998-99 models.
Valve lash is NOT adjustable on the 2.2L gasoline engine.
Install the rocker arm cover, then start and run the engine to check for leaks.