160. Ten laps later, debris was spotted in the turn two groove, causing the sixth caution, during which all the leaders made pit stops. Vickers led on the lap-174 restart, followed by Kurt Busch and Martin. Kurt Busch drove left to pass Vickers for the lead on lap 175; three laps later, Newman drove to his garage to retire with an engine failure. Mears' team installed a new battery into his car, and switched between his main and back-up battery to ensure engine power was maintained. Vickers retook the lead from Kurt Busch on the 181st lap, and Stewart got ahead of Kyle Busch one lap later. Johnson took the lead from Vickers on lap 184. On lap 185, Kurt Busch nudged the turn two wall with his right-rear side and spun on the backstretch, triggering the seventh caution. He regained control of his car to run in ninth place. Most of the leaders made pit stops. Johnson led at the lap-190 restart, followed by Vickers and Kenseth. Johnson held a one-second lead over Vickers by the 200th lap, by which time Edwards moved past Stewart. Vickers retook the lead from Johnson on lap 206. Fifteen laps later, the eighth caution was triggered when Edwards's car suffered a cut right-rear tire, slowed on the track and spun at turn four while driving cautiously to the pit road. Edwards collected his teammate, Ragan, who was run into by Elliott. Mears was close by the incident but avoided damaging his car. On lap 222, Vickers reported a power steering problem, and Kyle Busch was losing battery power. Most of the leaders, including Vickers, made pit stops. Kyle Busch's car had a replacement battery fitted and Vickers topped up with more fluids; both drivers rejoined in twelfth and thirteenth positions. Johnson led at the lap-227 restart, with Kenseth in second place. One lap later, Kenseth passed Johnson to take over first place, while Kyle Busch made heavy contact with the wall on his right side; a caution was not needed. Johnson reclaimed the first position from Kenseth on the backstretch on the 245th lap. Kyle Busch's right-front tire was cut, and went into the turn four wall on lap 252, triggering the ninth caution. During the caution, most of the leaders, including Johnson, chose to make pit stops. Johnson made changes to his car's left and right rear spring rubber, and Stewart's car's