The secondary air injection pump injects fresh air into the exhaust manifold downstream of the exhaust valves lowering the number of carbon emmissions that comeout of the vehicle. There are two pumps in the models this pump fits and you may have to buy two if both are not functional. The secondary air injection pump can easily be located inside the front passenger side wheel well. Compatible with the following: 2008-2013 LX570 5.7L 2008-2013 Land Cruiser 5.7L 2008-2009 Sequoia 4.7L, 5.7L 2010-2012 Sequoia 4.6L, 5.7L 2007-2009 Tundra 4.0L, 4.7L, 5.7L 2010-2011 Tundra 4.0L, 4.6L, 5.7L 2012-2013 Tundra 4.6L, 5.7L Replaces part numbers: 17610-0S010, 176100S010, 33-2504M, 10200231AA This is a compatible replacement part manufactured by AA Ignition. This air pump is NOT a genuine OEM part. Vehicle makes and their associated vehicle models and part numbers are used in this listing only to identify the vehicles this secondary air injection pump fits.