Download In some cases, owners of 2000 – 2002 model year Celica GTS vehicles equipped with the 2ZZ–GE engine may complain of an intermittent slight loss of power and/or variable lift function at engine speeds over 6,000 rpm under high load. This can be caused if the bolt securing the rocker shaft separates, allowing the shaft to rotate in its bore. This rotation, when it occurs, can cause misalignment of the oil feed passages to the rocker shafts, resulting in a lack of variable lift operation and low power at higher engine rpm. Repair Procedure 1. Remove Valve Cover A. Disconnect the negative and then the positive battery terminals. B. Remove the battery tie–down bracket and battery. C. Remove the 4 bolts and No. 2 cylinder head cover. (Figure 1.) D. Remove the ignition coils. (Figure 2.) E. Remove the wiring harness and protector from cylinder head cover.