STARTED WITH A #4 MISFIRE AND NO ENGINE POWER AND DEALER SAID TRUCK WAS FINE. FINALLY AFTER 4 CYLINDER MISFIRING, DEALER AGREED TRUCK HAD AN ISSUE AND IS NOW SAYING I NEED A VALVE JOB DONE FOR # 1800.00 BUT IT LOOKS LIKE I SHOULD TELL THEM THAT ITS THE LIFTERS.. 74,000 ON MY 2007 TAHOE FOR A 25,000.00 TRUCK NOT ONLY THAT BUT THEY ARE SAYING IF THAT DON'T FIX IT THEN I NEED TO PAY 3500.00 FOR A CAM SHAFT. ITS RUNNING BUT CHECK ENGINE LIGHT STAYS ON.