P1131 2003 Ford F150 5.4 engine

Question

Coolant leaking after replacing thermostat. Had coolant pushing up through coolant reservoir before changing thermostat. Now leaking when placed in drive. Now check engine light on and #7 coil needs to be replaced.

Answer 1

HI there,

This code is actually for a lack of O2 sensor switch. It also indicates a lean condition on bank 1.
P1131 FORD - Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 1

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