Sounds good thank you very much for this information! After lunch I will locate these three items and get them on order to see if this fixes my problem.

When I refer to the right or left side of the unit it will be inference to sitting in the seat.
So if you open the hood and on the left side of the engine you will see the air filter. From the air filter towards the engine you will find the LP Regulator prt #4148661 quantity 1. It is silver in color has two coolant hose's connected to it one on each side a electric solenoid valve on top with a hose coming to it from the LP tank and a third hose under one of the coolant hose's going to the Mixer/EPR.
C02 Sensors Prt # 1646456 quantity 2. One you will find screwed into the exhaust manifold and the manifold will be located directly under the LP Regulator under a heat shield the second one will be located on the exhaust pipe going to the catalytic converter which is located in the counter weight and can be accessed thru the back of the counter weight.

No problem, i'm also central time zone I just start super early lol.
The serial number is : P177V06130P
Model number: H60FT

What is the forklift serial number?

Once I get to my laptop at work I can help you better but that will not be until 8 or 9 central time zone

A nameplate on the engine itself shows GPSIB2.40GLP , Power Solutions International. Hopefully this is what you are looking for. I apologize as I don't deal with motors and this type of mechanical stuff hardly ever, so i'm not real familiar with it.

First I need to know what engine this forklift has.

Thank you for that information. I don't have a book for this machine, do you happen to know where these sensors and the LP converter is located in the machine?

Seeing how the code only appears once the engine has warmed up Which is a good indicator that the C02 sensors maybe failing or reading incorrectly when they heat up. I would replace the pre and post C02 sensors. Also since the operator stated that he smells LP in the cab that would be a good indicator that the LP Converter is failing and dumping fuel or flooding the engine with fuel. I would replace it as well.
Regards

Below is the service manual for the fault code you are having. Follow the troubleshooting guide and hopefully it will resolve your issue.

Heated Oxygen (O2) Sensor Circuit Signal Outside Of Acceptable Limits
CODES
DTC 522655-0 - Short Term Closed Loop Correction Bank 1 Less Than NOR -40% (Rich Engine Operation)
DTC 522655-1 - Short Term Closed Loop Correction Bank 1 Greater Than NOR 40% (Lean Engine Operation)
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)
POSSIBLE CAUSE
A. PROBLEMS THAT MAY CAUSE LEAN ENGINE OPERATION
B. PROBLEMS THAT MAY CAUSE RICH ENGINE OPERATION
C. SENSOR FAILURE
D. FUNCTIONAL FAILURE IN CONTROLLER
NOTE
Please refer to the end of this procedure for supporting diagrams.
COMPONENT OPERATIONAL CHECK
PROCEDURE OR ACTION:
1. Turn power to OFF for no less than 30 seconds, and then to ON to clear displayed DTC.
Does reported DTC reoccur?
YES: Go to Step 2.
NO: Problem not verified. Resume operation.
2. Conduct a quick visual inspection of all connectors/wiring associated with the displayed fault code.
Are any faults detected/observed?
YES:
* If DTC 522655-1 or 522660-1 occurs, go to Cause A.
* If DTC 522655-0 or 522660-0 occurs, go to Cause B.
Repair/replace connector or wiring associated with faults found. Refer to the appropriate Electrical System
SRM.
NO: Go to Cause A.
Diagnostic Trouble Codes Electrical System
Check the Service Manual section in Hypass Online for possible updates and check pertinent Grams
9030-20-492 Confidential/Proprietary - Do Not Copy or Duplicate
Heated Oxygen (O2) Sensor Circuit Signal Outside Of Acceptable Limits (Cont)
CAUSE A - PROBLEMS THAT MAY CAUSE LEAN ENGINE OPERATION
PROCEDURE OR ACTION:
NOTE: The following procedure does not specifically address the troubleshooting of the oxygen (O2
) sensor circuit but provides information relating to symptoms and other DTCs that need to be examined or resolved that may
cause this DTC to be displayed.
1. 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
2. If DTC continues to be displayed after examining/correcting the above, go to Cause C.
Electrical System Diagnostic Trouble Codes
Check the Service Manual section in Hypass Online for possible updates and check pertinent Grams
Confidential/Proprietary - Do Not Copy or Duplicate 9030-20-493
Heated Oxygen (O2) Sensor Circuit Signal Outside Of Acceptable Limits (Cont)
CAUSE B - PROBLEMS THAT MAY CAUSE RICH ENGINE OPERATION
PROCEDURE OR ACTION:
1. 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
2. If DTC continues to be displayed after examining/correcting the above, go to Cause C.
CAUSE C - SENSOR FAILURE
PROCEDURE OR ACTION:
1. Ensure truck power is OFF.
NOTE: Do not discard original sensor after removal.
2. Replace sensor.
3. Ensure that all connections are completely inserted.
4. Turn truck power ON.
Does reported DTC reoccur?
YES: Reinstall original sensor and go to Cause D. Refer to the appropriate Electrical System SRM.
NO: Problem has been corrected. Resume operation. Discard faulty sensor.
Diagnostic Trouble Codes Electrical System
Check the Service Manual section in Hypass Online for possible updates and check pertinent Grams
9030-20-494 Confidential/Proprietary - Do Not Copy or Duplicate
Heated Oxygen (O2) Sensor Circuit Signal Outside Of Acceptable Limits (Cont)
CAUSE D - FUNCTIONAL FAILURE IN CONTROLLER
PROCEDURE OR ACTION:
1. Ensure all previous procedures have been completed.
2. Ensure truck power is OFF.
3. Ensure that all connections to the controller are completely inserted.
4. Ensure truck power is OFF for no less than 30 seconds, and then to ON to clear displayed DTC.
Does reported DTC reoccur?
YES: Go to Step 5.
NO: Problem corrected. Resume operation.
5. At the DSC, press ENTER to access Main Menu.
6. Scroll to VIEW VERSIONS, press ENTER.
7. Scroll to TRUCK SERIAL NUMBER, press ENTER.
8. View the TRUCK SERIAL NUMBER on the display.
Does the truck serial number on display match serial number on truck nameplate (VSM Only)?
YES: Go to Step 9.
NO: Controller has been substituted from another truck. Replace VSM with VSM that has the correct truck
serial number or obtain new VSM with correct Serial number/ CDF. Refer to the appropriate Electrical System SRM.
9. Resident Service Approval Required prior to VSM replacement for Trucks under warranty. Make sure
to indicate the DTC code(s) on the warranty claim and include an accurate problem description leading to the
controller replacement.
10. For other controllers, Replace indicated controller. (ECU-ECM/GCU/TCU). Refer to the appropriate Electrical
System and Engine Fuel System SRM for all controllers.
11. Reinstall all removed components and ensure that all connectors are completely inserted.
NOTE: For Post 2007 Engine Connectors Interface, see Post 2007 Engine Connections.
12. Repeat Component Operational Check.
END POSSIBLE CAUSES