2013 coil ground terminal location for catalytic convertor?

[Andreash_utah]

My 2013 LaCrosse V6 has 49k miles on it and is throwing the dreaded p0420 and p0430 codes. Had a complete test done at the shop and was told both catalytic convertors, 02 sensor, and MAF sensor are working fine. I don't really want to pay for new cats after the mechanic tells me nothing's wrong. 😒

Today, I stumbled across this article: https://static.nhtsa.gov/odi/tsbs/2016/MC-10113914-9999.pdf. It's worth a shot. Can someone tell me where the coil ground terminals for each bank is located?

 

[LARRY70GS]

IMHO, that is not your problem. You would have misfires. Enough of them would set a misfire code. A good scan tool will have a misfire counter by cylinder. You can check that, but I doubt you'll see any misfires.

A cheap and easy solution is to just buy an O2 sensor extender and try that. They work by spacing out the rear O2 sensor so they get a smaller sample. Many have eliminated P0420 and 430 codes that way.

 

[douger]

First, the diagnostics for the code.



Conditions for Running the DTC

• DTC P0016, P0017, P0018, P0019, P0053, P0054, P0059, P0060, P0068, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0135, P0137, P0138, P013A, P013B, P013C, P013D, P013E, P013F, P0140, P0141, P014A, P014B, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0191, P0192, P0193, P0222, P0223, P0300, P0301. P0302, P0303, P0304, P0305, P0306, P0335, P0336, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0443, P0506, P0507, P0606, P1153, P16F3, P2101, P2122, P2123, P2127, P2128, P2135, P2138, P2227, P2228, P2229, P2230, P2270, P2271, P2272, or P2273 is not set.
• Before the ECM performs the idle test, the vehicle must be driven under the following conditions:
  • Engine speed is greater than 965 RPM
  • Engine run time is greater than a calibrated value
  • Both conditions exist for greater than 15 s
• Throttle is in the rest position.
• Intake air temperature (IAT) is between −20 to +250°C (−4 to +482°F).
• Ignition voltage is greater than 11 V.
• Engine coolant temperature (ECT) is between 40–127°C (104–261°F).
• Barometric pressure (BARO) is greater than 70 kPa.
• Engine has been idling less than 50 s.
• Vehicle speed is less than 2 km/h (1 mph).
• Short term fuel trim is learned.
• Mass air flow (MAF) is between 3–13 g/s.
• Evaporative emissions (EVAP) purge concentration is learned.
• Catalytic converter calculated temperature is between 450–850°C (842–1,562°F).
• Engine is operating in closed loop.
• Transmission is not in P/N (automatic transmission only).

This diagnostic attempts one test during each valid idle period once the above conditions have been met. This diagnostic attempts up to 8 tests during each drive cycle.

Conditions for Setting the DTC
The ECM determines that the efficiency of the catalyst has degraded below a calibrated threshold.

Action Taken When the DTC Sets
DTC P0420 and P0430 are Type A DTCs.

Conditions for Clearing the DTC
DTC P0420 and P0430 are Type A DTCs.

Diagnostic Aids
Inspect for the conditions listed below, which may cause a catalyst to degrade:

• Engine misfire
• High engine oil or high coolant consumption
• Retarded spark timing
• Weak or poor spark
• Lean fuel mixture
• Rich fuel mixture
• Damaged oxygen sensor or wiring harness

Reference InformationDTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
Control Module References for scan tool information

Circuit/System Verification

1. Ignition On.
2. Verify there are no other DTCs set.
   • If other DTCs are set
     Refer to Diagnostic Trouble Code (DTC) List - Vehicle.
   • If no other DTCs are set
3. Operate the vehicle within the Conditions for Running the DTC.
4. Verify the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter changes to Yes.
   • If Yes is not displayed
     Refer to step 3.
   • If Yes is displayed
5. When the conditions are safe, stop and idle the vehicle in gear if equipped with automatic transmission or neutral if equipped with manual transmission.
6. Verify the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters display Passed when performing the steps listed below:
   1. Apply the service brake.
   2. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.
   3. Note: When the test has completed, the Catalyst Monitor Test Counter Bank 1 and Bank 2 parameters will increment by one and the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters will indicate Passed, Failed or No Result.
   4. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.
   5. Verify the scan tool Catalyst Monitor Test Result Bank 1 or Bank 2 parameter displays Passed.
   6. If No Result is displayed
      Repeat steps 3–6 until the Test Result parameters indicate Passed or Failed.
   7. If Failed is displayed
      Refer to Circuit /System Testing.
   8. If Passed is displayed
7. All OK.

Circuit/System Testing

1. Verify the conditions listed below do not exist with the appropriate catalytic converter:
   • Dents
   • Severe discoloration caused by excessive temperatures.
   • Road damage.
   • Internal rattles caused by damaged catalyst substrate.
   • Restrictions
     • If a condition is found
       Replace the catalytic converter.
     • If no condition is found
2. Verify the conditions listed below do not exist with the exhaust system:
   • Leaks.
   • Physical damage.
   • Loose or missing hardware.
     • If a condition is found
       Repair or replace the component as necessary.
     • If no condition is found
3. Verify the conditions listed below do not exist with the appropriate B52B Heated Oxygen Sensor 2:
   • The HO2S is not at the correct torque.
   • Damage.
     • If a condition is found
       Replace the B52B Heated Oxygen Sensor 2 or repair the condition as necessary.
     • If no condition is found
4. Replace the catalytic converter.

Repair Instructions
Note: A new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

• Catalytic Converter Replacement - Left Side
• Catalytic Converter Replacement - Right Side
• Exhaust Leakage
• Heated Oxygen Sensor Replacement - Bank 1 Sensor 2
• Heated Oxygen Sensor Replacement - Bank 2 Sensor 2
• Perform the HO2S Heater Learn procedure with a scan tool after replacing the Heated Oxygen Sensor.
• Restricted Exhaust

Repair Verification

1. Install any components that have been removed or replaced during diagnosis.
2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
3. Clear the DTCs with a scan tool.
4. Turn Off the ignition for 60 s.
5. Operate the vehicle within the Conditions for Running the DTC.
6. Verify the scan tool Catalyst Monitor Not At Idle Test Conditions Met parameter changes to Yes.
   • If Yes is not displayed
     Refer to step 5.
   • If Yes is displayed
7. When the conditions are safe, stop and idle the vehicle in gear if equipped with automatic transmission or neutral if equipped with manual transmission.
8. Verify the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters display Passed when performing the steps listed below:
   1. Apply the service brake.
   2. Monitor the scan tool Catalyst Monitor Test State parameter. When the parameter indicates Active, the Catalyst Monitor Test is running.
   3. Note: When the test has completed, the Catalyst Monitor Test Counter Bank 1 and Bank 2 parameters will increment by one and the Catalyst Monitor Test Result Bank 1 and Bank 2 parameters will indicate Passed, Failed or No Result.
   4. Continue to monitor the parameter. When the parameter indicates Inactive, the Catalyst Monitor Test has completed.
   5. Verify the scan tool Catalyst Monitor Test Result Bank 1 or Bank 2 parameter displays Passed.
   6. If No Result is displayed
      Repeat steps 5–8 until the Test Result parameters indicate Passed or Failed.
   7. If Failed is displayed
      Refer to Circuit /System Testing.
   8. If Passed is displayed
9. All OK.
   
   I'm thinking GM wants to steer the tech towards leaks.