LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2007 >> Wrangler X, Standard >> Repair and Diagnosis >> Engine Performance >> System >> DTCS P0642 To P1602 >> P1128-Closed Loop Fueling Not Achieved - Bank 1 >> Possible Causes
September 30: LEMON manuals is back up on a temporary server! Slowness is possible

Possible Causes

Possible Causes 
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SIGNAL CIRCUIT
O2 RETURN CIRCUIT
1/1 O2 SENSOR
MAP SENSOR
ECT SENSOR
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR (HIGH)
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .