Time for the dreaded emissions inspection test. Had to reload my basic stock tune minus the rear O2 sensors (they were deleted via HP Tuners) as I'm running LG longtubes. Been driving for a few days in hopes of getting the readiness tests to complete, but can't seem to get the catalyst readiness test to show complete.
Would the deleted rear O2 sensors be causing this or isit just a matter of time (i.e drive cycles) before it finally shows complete? If its the lack of rear O2 sensors I take it its time for sims?
Inspection/Maintenance (I/M) Catalyst System Set Procedure
Description
The purpose of this test is to satisfy the enable criteria necessary to execute inspection maintenance (I/M) readiness diagnostics for the Catalyst System. The test may be used in order to set the I/M System Status indicators to YES. Ensure that the vehicle meets the requirements listed in Conditions for Running before performing this test. Failure to meet the necessary requirements may produce inaccurate test results.
Conditions for Running
The barometric pressure is more than 74 kPa.
The engine coolant is at the operating temperature, 71-120°C (160-248°F).
The intake air temperature (IAT) is between -15-75°C (5-167°F).
The engine is in Closed Loop Fuel Control.
The engine has run for 6-8 minutes off idle in order to initiate test.
The battery voltage is between 11-18 volts.
Diagnostic Aids
The control module runs a maximum of 6 tests per trip until the Catalyst System Status updates to YES. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.
The I/M System Status does not indicate whether the test has passed or failed, only that a decision was made. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the required tests have not run. When a failure occurs, the Emission Related DTC portion of the I/M System Status display will indicate the malfunction indicator lamp (MIL) is requested. The I/M System Status also registers the number of diagnostic trouble codes (DTCs).
The first failure of a type B DTC does not constitute a final determination of pass or fail, and will not update the I/M System Status to YES. A second trip is required, and all the conditions to run must be met in order for the test to run again. These conditions may include a partial to complete engine cool down.
The I/M System Status will update only when an emission related DTC fails the second time, or when all of the tests pass.
If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.
If a diagnostic test is difficult to run, maintain necessary enable conditions until the system status updates to YES.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Make sure you perform the I/M System Check before performing this test. Failure to do so may result in difficulty updating the status to YES.
Perform the Catalyst Test during the idle period immediately following the cruise period.
This step is to identify a first failure of a type B DTC. A DTC only appears on the I/M System Status display when the DTC becomes a MIL illuminating DTC. This occurs on the second failure of a type B DTC. A first failure of a type B DTC will not allow the I/M System Status to update to YES. Refer to Diagnostic Aids.
This step is to help identify any unique or unusual criteria required to run the diagnostic test in the event the universal set procedure does not. This information is located in the service information under Conditions for Running the DTC.
The I/M System Status only reports on whether or not a diagnostic has run, not what the outcome of the test was. If any emission related DTC sets after the tests are complete, the DTC will require diagnosis.
Step
Action
Yes
No
1
Did you perform the Inspection/Maintenance (I/M) System Check?
Go to Step 2
Go to Inspection/Maintenance (I/M) System Check
2
Ensure the vehicle is within the Conditions for Running specified in the supporting text.
Turn OFF all of the accessories, including the A/C and the blower fan.
Start the engine. Allow the engine to idle.
Caution
Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
Important
In order for this test to run, the vehicle must operate in the following conditions:
Acceleration at part throttle to 90 km/h (55 mph), with this speed maintained for 5 minutes
Deceleration to 0 km/h (0 mph)
Engine idling for 2 minutes while the following criteria are maintained:
Service brake depressed
Automatic transmission in Drive
Manual transmission in Neutral with the clutch pedal depressed
With a scan tool, observe the I/M System Status display.
Did the Catalyst System Status update to YES?
Go to Step 5
Go to Step 3
3
With a scan tool, observe the DTC Information.
Does the scan tool indicate any failed DTCs?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 4
4
Refer to Inspection/Maintenance (I/M) System DTC Table to determine which DTCs are required to run in order to complete this test.
With a scan tool, observe the Not Ran Since Code Cleared display.
Determine which of the DTCs required for a YES status has not run.
Enter the DTC number in the Specific DTC menu of the scan tool.
Operate the vehicle within the Conditions for Running the DTC, located in the supporting text for the diagnostic table of the DTC.
Repeat the procedure until the scan tool indicates the diagnostic test has run.
Repeat steps 4-6 for any additional required DTCs that have not run.
With a scan tool, observe the I/M System Status display.
Did the Catalyst System Status update to YES?
Go to Step 5
Go to Diagnostic Aids
5
With a scan tool, observe the Emission Related DTC portion of the I/M System Status display.
Does the scan tool indicate any Emission Related DTCs set?
Go to Diagnostic Trouble Code (DTC) List
System OK
Inspection/Maintenance (I/M) System Check
Description
Several states require that a vehicle pass on-board diagnostic (OBD) system tests and pass the inspection maintenance (I/M) emission inspection in order to renew the license plates. This is accomplished by viewing the I/M System Status display on a scan tool. Using a scan tool, the technician can observe the I/M System Status in order to verify that the vehicle meets the criteria that comply with the local area requirements.
Conditions for Updating the I/M System Status
Each system requires at least 1, and sometimes several, diagnostic tests. The results of these tests are reported by a diagnostic trouble code (DTC). A system monitor is complete when either all of the DTCs comprising the monitor have run and passed, or when any 1 of the DTCs comprising the monitor have illuminated the MIL. Once all of the tests are completed, the I/M System Status display will indicate YES in the Completed column. For example, when the HO2S Heater Test indicates YES, all of the oxygen sensor heaters have been diagnosed. If the vehicle has 4 heated oxygen sensors, all 4 heater circuits have been diagnosed. The I/M System Status will indicate NO under the Completed column when any of the required tests for that system have not run. The following is a list of conditions that will set the I/M System Status indicator to NO:
The vehicle is new from the factory and has not yet been driven through the necessary drive conditions to complete the tests.
The battery has been disconnected or discharged below the operating voltage.
The control module power or ground has been interrupted.
The control module has been reprogrammed.
The control module DTCs have been cleared as part of a service procedure.
Monitored Emission Control Systems
The OBD II System monitors all emission control systems that are on-board. Not all vehicles have a full complement of emission control systems. For example, a vehicle may not be equipped with AIR or EGR. The OBD II regulations require monitoring of the following:
The air conditioning system
The catalytic converter efficiency
Comprehensive component monitoring of the emission-related inputs and outputs
The evaporative emissions (EVAP) system
The exhaust gas recirculation (EGR) system
The fuel delivery system
Heated catalyst monitoring
Misfire monitoring
The oxygen sensor system (O2S or HO2S)
The oxygen sensor heater system (HO2S heater)
The secondary air injection (AIR) system
For the specific DTCs required for each system, refer to Inspection/Maintenance (I/M) System DTC Table . Systems such as the fuel delivery, the misfire, and the comprehensive components may not be listed in a system status list. These tests run continuously on some vehicles, and may not require an indicator.
Diagnostic Aids
The I/M System Status display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, the failure may prevent other required tests from running. For example, a DTC for the control circuit of the relay controlling an AIR pump may not be listed in the Inspection/Maintenance System DTC Table because the DTC is a continuous test. If this DTC is set, the Active Tests for the AIR system may not run.
The I/M System Status information may be useful for a technician to determine if diagnostics have run when verifying repairs.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Any DTCs that set, even DTCs that are not listed in the Inspection/Maintenance System DTC Table, may prevent the required DTCs from running. If there is any question as to whether a set DTC is disabling the required I/M diagnostic, review the Conditions for Running in the diagnostic procedures for the DTC that is required by the I/M diagnostic. A list of disabling DTCs, if applicable, is in the supporting text for that DTC.
When a control module is reprogrammed or when the diagnostic trouble codes are cleared as part of a repair procedure, all the I/M System Status indicators will reset to NO.
Use discretion when determining whether the entire system set procedure needs to be performed. For example, if the only tests that have not run are tests that require the engine to be at operating temperature, then only those individual tests need to be run. There is no need to allow the engine to completely cool in order to run these tests.
Step
Action
Yes
No
1
Perform Diagnostic System Check - Engine Controls .
Important
Many DTC-related repairs instruct the technician to clear the DTC information. This procedure will reset ALL of the I/M System Status indicators to NO, and require performing the I/M Complete System Set Procedure.
Repair any DTCs or driveability concerns that would prevent the I/M System Status tests from completing.
Did you find and repair a DTC or a driveability concern?
Go to Step 3
Go to Step 2
2
Review any service bulletins for software updates that may prevent I/M readiness.
Perform any reprogramming or repairs indicated by the service bulletins.
Was a reprogramming or repair service required?
Go to Inspection/Maintenance (I/M) Complete System Set Procedure
Go to Step 3
3
With a scan tool, observe the I/M System Status display.
Is more than one test indicating a NO status?
Go to Inspection/Maintenance (I/M) Complete System Set Procedure
Go to the I/M System Set Procedure for the indicated system
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Well, I followed the instructions above and drove the GM drive cycle countless times. Add to that multiple cold and warm starts, but still can't seem to get the catalyst readiness test to show complete...
Sadly, I need this test to show complete to pass NYS inspection. Any ideas? I am using my stock tune with the only exception being that the rear O2s have been deleted (LG Longtubes). Haven't cleared codes, changed the tune or done anything to cause the PCM to reset the readiness tests. HP Tuners shows no DTC codes (history, current or otherwise)....
Here's what I did to edit out the rear O2s. All have been set to "No error reported" and SES light still enabled.
Driver Side
P0136 - H02S Circuit Bank 1 Sensor 2
P0137 - HO2S Circuit Low Voltage Bank 1 Sensor 2
P0138 - HO2S Circuit High Voltage Bank 1 Sensor 2
P0140 - HO2S Circuit Insufficient Activity Bank 1 Sensor 2
P0141 - HO2S Heater Performance Bank 1 Sensor 2
P0420 - Catalyst System Low Efficiency Bank 1
Passenger Side
P0156 - H02S Circuit Bank 2 Sensor 2
P0157 - HO2S Circuit Low Voltage Bank 2 Sensor 2
P0158 - HO2S Circuit High Voltage Bank 2 Sensor 2
P0160 - HO2S Circuit Insufficient Activity Bank 2 Sensor 2
P0161 - HO2S Heater Performance Bank 2 Sensor 2
P0430 - Catalyst System Low Efficiency Bank 2
Am I missing something or is it just a matter of time?
If you have removed the rear 02s and set them to "no error", that doesn't tell the PCM to make pretend they're not there, it just tells the PCM not to set the SES light and code. But unfortunately, the Catalyst Ready test is still looking for those 02s and their absence is preventing the cycle from completing. But note the service manual says the readiness test will "complete" regardless of whether or not any of the tests fail. I suspect if you put the 02s back on the connectors, even though they won't be in the exhaust stream and "work", the readiness test will complete and your problem would be solved. Strap the 02s up under the car someplace with zipties and see if the test will go to "done" state. If it does, get your inspection and then remove the sensors again...
Thank you for the input, but I figured out my error. I inadvertently set the codes listed below to "3 - No error reported" and unchecked the SES light.
P0420 - Catalyst System Low Efficiency Bank 1
P0430 - Catalyst System Low Efficiency Bank 2
I recall somewhere, someone had said not to un-check the SES light. I looked over my tune and realized I had unchecked the SES light on theabove DTCs. Once I re-enabled the SES light, the Catalyst readiness test immediately showed as Complete...
So, in summary, if you have Longtubes and removed the rear 02 sensors, set Error Mode to "3-No error reported" and leave the SES enabled on the DTC codes I listed in my original post and the Catalyst readiness test will show complete.. Hope this helps somebody in the future.
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