Before beginning this procedure, ensure the transmission is in Park or Neutral, apply the parking brake, and block the rear wheels. Disconnect the cable from the negative terminal of the battery. Remove the camshafts. For 2002 models with the type 111 engine, which uses bucket-type hydraulic cam followers actuated directly by the cam lobes, push down on each follower with a wooden dowel to check its action; if any compresses more easily, replace all followers as a set, taking care not to push the valve off its seat. Use a suction cup tool to remove the cam followers from the cylinder head, checking for wear on the friction surfaces, and store them upright in clean engine oil to prevent bleeding down. Inspect each cam follower for scoring or wear, and if one is bad, replace all as a set. Installation is the reverse of removal, ensuring lubrication with clean engine oil before installation. For 2003 through 2005 models with the type 271 engine, which uses rocker arms and hydraulic lash adjusters, label and store the rocker arms and lash adjusters separately for reinstallation. Push on the lash adjuster end of each rocker arm; if any compresses easily, replace all lash adjusters as a set, avoiding excessive force. Remove each rocker arm, which will bring the hydraulic lash adjuster out with it, and push off the retaining clip to separate the lash adjuster from the rocker arm, storing them in clean engine oil. Check the lash adjusters for wear and ensure they move freely without excessive play; if one is worn, replace all as a set. Inspect each rocker arm for wear, cracks, and damage, ensuring the rollers turn freely. Installation is the reverse of removal, with lubrication of the lash adjusters and rocker arm surfaces with clean engine oil before installation.