This code is set when the engine is running too rich or too lean. There could be several issues, I would start with monitoring the oxygen sensor voltage and see if it is staying above .5 volts (rich) or below .5 volts (lean for too long. The voltage should switch fairly rapidly above and below .5 volts when working properly.
A lean condition can be caused by a vacuum leak, a plugged fuel filter or an empty or low fuel tank.
DTC 522660-0 – Long Term Closed Loop Correction Bank 1 Less Than NOR -35% (Rich Engine Operation)
DTC 522660-1 – Long Term Closed Loop Correction Bank 1 Greater Than NOR 35% (Lean Engine Operation)
PROBLEMS THAT MAY CAUSE LEAN ENGINE OPERATION
Common problems that may cause lean codes:
• Contaminated/clogged trim fuel injector’s filter and/or LPG regulator’s filter
• Contaminated/clogged trim fuel injector
• Faulty trim fuel injector or wiring
• Contaminated LPG fuel
• Low primary LPG fuel pressure (for trim fuel injector)
• Low secondary LPG fuel pressure (for carburetor)
• Clogged fuel hoses
• Contaminated/dirty carburetor
• Faulty fuel shutoff solenoids
• Engine overheating
• Exhaust leaks prior to or near oxygen (O2) sensor
• Manifold vacuum leaks
• Improper ECU grounds on engine block
• Faulty ECU injector driver 2
PROBLEMS THAT MAY CAUSE RICH ENGINE OPERATION
Common problems that may cause rich codes:
• Clogged/dirty air filter
• Fuel quality (Very high butane content)
• Operation at high altitudes
• High primary fuel pressure (for trim fuel injector)
• Faulty trim fuel injector or wiring
• Faulty LPG carburetor (power valve stuck open)
• Faulty LPG regulator
• Manifold vacuum leaks
• Improper ECU grounds on engine block
• Faulty ECU injector driver 2