01MYCoupe/Auto/114,000 miles, 22mpg town / 27mpg hwy Car meticulously maintained by Corvettes of Houston.
DIC displays the following:
PO171 Fuel Trim System Lean Bank 1-B
PO174 Fuel Trim System Lean Bank 2-B
P1416 Air System Bank 2-B
What is the fix to keep these freakin codes from coming up?
Thanks in advance
EELSTX

 

Sounds like an exhaust leak at the AIR on the header.

 

The PCM is setting codes 171 and 174 because it’s having to add more fuel than it thinks should be necessary to get the front O2 sensors of both banks to cross from lean to rich. Fuel trims more than +25%. You or someone will have to figure out why. Codes don’t tell you the answer, they just point you in the right direction. You still gota do some work….. Like maybe look for a vac. leak???

Not sure if the 1416 could be related to a vacuum leak but the PCM does look to the 02 sensors to confirm air injection. Maybe if the 02 is already a little lean….? At any rate I would take a quick look at the air injection hoses, check valves and connections then move on to the 171-174 first. JMHO, good luck.

 

As mentioned before you will have to do some work. These codes could have a common cause so you need to analyze the problem Vs trying to throw some parts at the car. Here are the diagnostic procedures for the codes:

DTC P0171 or P0174
Circuit Description
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the PCM determines fuel delivery based on sensor signals without oxygen sensor (O2S) input. During Closed Loop, the O2S inputs are added and used by the PCM to calculate short and long term fuel trim fuel delivery adjustments. If the O2S indicate a lean condition, fuel trim values will be above 0 percent. If the O2S indicate a rich condition, fuel trim values will be below 0 percent. Short term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the PCM detects an excessively lean condition, DTC P0171 or P0174 sets.

Conditions for Running the DTC
DTCs P0101, P0103, P0108, P0135, P0137, P0141, P0200, P0300, P0410, P0420, P0430, P0440, P0442, P0443, P0446, P0449, P0506, P0507 or P1441 are not set.
The engine coolant temperature (ECT) is between 75-115°C (167-239°F).
The intake air temperature (IAT) is between -20 to +90°C (4-194°F).
The manifold absolute pressure (MAP) is between 26-90 kPa (3.7-13 psi).
The vehicle speed is less than 137 km/h (85 mph).
The engine speed is between 400-3,000 RPM.
The barometric pressure (BARO) is more than 74 kPa (10.7 psi).
The mass airflow (MAF) is between 5-90 g/s.
The fuel level is more than 10 percent.
The throttle position (TP) is less than 90 percent.
.

Conditions for Setting the DTC
The average long term fuel trim cell value is above 23 percent.
All of the above conditions are present for 6 seconds.
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
The system will go lean if an injector is not suppling enough fuel.
A lean condition could be present during high fuel demand.
Use a scan tool in order to review the Failure Records . If an intermittent condition is suspected, refer to Intermittent Conditions .
Test Description
The numbers below refer to the step numbers on the diagnostic table.

If conditions were not corrected, refer to Fuel System Diagnosis for a possible fuel problem.

If conditions were not corrected, a worn cam, worn intake or exhaust valves, or other engine mechanical failure may be the problem.

Step
Action
Values
Yes
No

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2

Important
If any DTCs other than P0171 or P0174 are set, refer to those DTCs before continuing.


Install the scan tool.
Start and idle the engine at the normal operating temperature in Closed Loop.
Record the long term fuel trim.
Turn OFF the engine.
Turn ON ignition, with engine OFF.
Review the Freeze Frame/Failure Records and record the displayed data for this DTC.
Does the scan tool indicate that the long term fuel trim is greater than the specified value?
23%
Go to Step 3
Go to Diagnostic Aids

3
Operate engine at idle.
Observe the HO2S parameters with a scan tool.
Does the scan tool indicate that the parameter is within the specified range and fluctuating?
200- 800 mV
Go to Step 4
Go to Step 5

4
Turn OFF the engine.
Visually and physically inspect the following items:
The vacuum hoses for splits, kinks, and proper connections--Refer to Emission Hose Routing Diagram .
Ensure that the vehicle has sufficient fuel in tank. If fuel pressure is too low this DTC may set. Refer to Fuel System Diagnosis .
Fuel contamination--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Did you find and correct the condition?
--
Go to Step 7
Go to Step 6

5
Turn OFF the engine.
Inspect the HO2S for proper installation.
Verify the electrical connectors and the wires are secure, and not contacting the exhaust system.
Test for continuity between the HO2S signal circuit and the low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 7
Go to Fuel System Diagnosis

6
Operate the engine at idle.
Inspect for any missing, loose, or leaking exhaust components forward of the HO2S.
Inspect for vacuum leaks at the intake manifold, throttle body, and injector O-rings.
Inspect the air induction system and the air intake ducts for leaks.
Inspect the secondary air injection (AIR) system for leaks, improper air delivery, and for the shut-off valves not closing.
Inspect the crankcase ventilation system for leaks. Refer to Crankcase Ventilation System Inspection/Diagnosis in Engine Mechanical.
Did you find and correct the condition?
--
Go to Step 7
Go to Symptoms - Engine Mechanical in Engine Mechanical

7

Important
After repairs, use the scan tool Fuel Trim Reset function in order to reset the Long Term Fuel Trim.


Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
--
Go to Step 2
Go to Step 8

8
Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK

DTC P1415 or P1416
Circuit Description
The secondary air injection (AIR) pump system is designed to lower exhaust emission levels after a start up. The AIR pump is timed to remain ON for approximately 1 minute after the engine is started.

The powertrain control module (PCM) commands the AIR pump relay ON by supplying a ground to the AIR pump relay control circuit. This action energizes the AIR pump, forcing fresh air into the exhaust stream. The PCM also commands the AIR vacuum control solenoid ON which applies engine vacuum to the AIR shut-off valve. With vacuum applied to the AIR shut-off valve, airflow from the AIR pump flows through the pipes/hoses to the exhaust check valves, then enters into the exhaust stream. The air, oxygen, that is introduced into the exhaust system accelerates catalyst operation. When inactive, the check valves and the shut-off valve prevent air flow in either direction.

The PCM detects a system air flow condition by monitoring the heated oxygen sensors (HO2S) and Short Term Fuel Trim during normal Open Loop AIR system operation. This is called a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the diagnostic will proceed with an intrusive or active test. The PCM will command the AIR system ON during Closed Loop operation under normal operating conditions. The active test will pass or fail based on the response from the HO2S. A lean HO2S response indicates that the AIR system is functioning normally. An increasing Short Term Fuel Trim value also indicates a normal functioning system. The AIR diagnostic consists of the passive test and the active tests. The AIR diagnostic requires failure of the passive and active tests on 2 consecutive key cycles to illuminate the malfunction indicator lamp (MIL) and stores a DTC. If the PCM detects that the HO2S and Short Term Fuel Trim did not respond as expected on one of the engine banks, DTC P1415 or P1416 sets.

Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0151, P0154, P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0200, P0300, P0335, P0336, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P0440, P0442, P0443, P0446, P0449, P1120, P1133, P1134, P1153, P1154, P1220, P1221, P1258, P1441 are not set.
The engine is running for more than 30 seconds.
The mass air flow (MAF) is less than 23 g/s.
The air/fuel ratio is 14.7:1.
The engine load is less than 40 percent.
The ignition voltage is more than 11.7 volts.
The engine is not operating in the Power Enrichment, the Decel Fuel Shut-off, or the Catalyst Over-Temperature Modes.
The engine speed is more than 850 RPM.
The engine coolant temperature (ECT) is between -10 and +110°C (14-230°F) .
The intake air temperature (IAT) is between -10 and +100°C (14-212°F) .
The fuel system is operating in fuel trim cells 1, 2, 4, 5, or 6.
Conditions for Setting the DTC
The HO2S voltage does not decrease to less than 222 mV for 1.3 seconds.

OR

The short-term fuel trim does not change more than a predetermined value.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
For any test that requires probing the PCM or probing a component harness connector, use the J 35616-A connector test adapter kit . Using this kit prevents damage to the harness or component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
Carbon build-up in the exhaust manifold may restrict the amount of air flow necessary to affect the HO2S voltage. If you suspect this condition, remove the air pipe from the manifold and inspect the passage.
For an intermittent condition, refer to Intermittent Conditions .
Inspect for the following conditions:
Excessive exhaust system back pressure
Moisture, water, or debris ingestion into the AIR pump
Leaking check valves will leave traces of exhaust carbon in the AIR system.
A vacuum solenoid leaking vacuum will hold the shut-off valve open an exhaust noise may be heard through the air cleaner fuel trims at idle may be higher than normal a DTC may not set.
The vacuum lines at the vacuum solenoid cannot be reversed.
A check valve that flows in both directions causes heat damage to the AIR system components.
Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Start and idle the engine until Closed Loop is achieved.
Turn OFF all the accessories.
Monitor the HO2S bank 1 sensor 1 and bank 2 sensor 1 voltage parameters for the applicable bank with a scan tool.
Command the AIR system ON with a scan tool.
Observe and record the HO2S voltage as the AIR system is enabled.
Does the HO2S voltage decrease to less than the specified value?
222 mV
Go to Diagnostic Aids
Go to Step 3

3
Perform a visual inspection of all pipes/hoses in the AIR system for the following conditions:

Loose or missing clamps on the AIR pipes/hoses
No kinks, holes, or pinched hoses/pipes
Components with evidence of heat damage
Did you find and correct a condition?
--
Go to Step 7
Go to Step 4

4
Remove the crossover hose from the applicable check valve.
Command the AIR pump relay ON with a scan tool.
Is air flow present at the hose outlet?
--
Go to Step 6
Go to Step 5

5
Repair the restriction or the leak for the applicable bank in the AIR crossover pipes/hoses between the exhaust check valve and the AIR shut-off valve.

Did you complete the repair?
--
Go to Step 7
--

6
Repair the restriction/leak or blockage for the applicable bank in one of the following components:

The exhaust check valve. Refer to Secondary Air Injection (AIR) Check Valve/Pipe Replacement - Bank 1 or Secondary Air Injection (AIR) Check Valve/Pipe Replacement - Bank 2
The exhaust check valve outlet pipe
The exhaust manifold
Did you find and correct a condition?
--
Go to Step 7
--

7
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition?
--
Go to Step 2
Go to Step 8

8
Observe the Capture Info with a scan tool.

Are there any DTCs that you have not yet diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK

Bill

 

Thanks a lot for the input. Looks like I'll be taking the car to Corvettes of Houston to resolve the problem.
Once again, I appreciate the input.
EELSTX

 

Question??
I get this code P1416 mod 10 bank 2 secondary air injection system