P0131 Mazda

Fix code P0131 Mazda P2251 Mazda

If you have either P0131, P2251 on a 2007-2009 Mazda3 (not including Mazdaspeed3) or 2007-2010 Mazda5 vehicles with a VIN lower than JM1CR*****367196 produced before November 6, 2009, this may be your fix. In these vehicles, the air fuel sensor connector bracket may contact and damage the sensor harness. Before you automatically replace the expensive air fuel ratio sensor, check the harness and bracket

First, if the harness shows damage, bend the sensor harness connector bracket to prevent interference, then replace the A/F sensor with a new one. Cover the tips of pliers with vinyl tape to prevent damage to the surface of the bracket. Then bend the bracket to make clearance between the harness and the edge of the bracket by 8 mm or more. DO NOT bend the clip to avoid breakage.

However, if the harness is not damaged, conduct the normal troubleshooting tecniques shown in the shop manual.  Cover the tips of pliers with vinyl tape to prevent damage to the surface of the bracket.

DTC P0131: A/F sensor circuit low input

DTC P2251: A/F sensor negative current control circuit open

©, 2014 Rick Muscoplat