Caterpillar Fault Code
Free · no signupSPN 157 FMI 18
Engine Bogging.
System
Not specified
Symptom
Engine Bogging.
Diagnosis & fix steps
LOGIC: Injector Metering Rail 1 Pressure Low.
ACTION: Replace primary/secondary fuel filters; check for air in the suction line.
Red Seal field insights
Red Seal Fix: Often caused by a failing electric lift pump. If the fuel tank is below 1/4, the pump has to work harder and can't maintain rail pressure.
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