Trouble Code P1133

[03BlackBeast]

I drive an '03 with a 4.8, and after a huge fiasco with the dealership, and swapping and cleaning MAFs, my truck is throwing the P1133 code. I've checked the Haines manual and it states that it is "Oxygen sensor insufficient switching (pre-converter sensor, left bank). What does this mean exactly? Ive checked the other threads related to this, and I noticed the cats were mentioned. Only problem is I have none, and Nelson Performance adjusted the tune accordingly. Any suggestions as to what is causing this? Many thanks.

[j cAT]

Originally Posted by 03BlackBeast

I drive an '03 with a 4.8, and after a huge fiasco with the dealership, and swapping and cleaning MAFs, my truck is throwing the P1133 code. I've checked the Haines manual and it states that it is "Oxygen sensor insufficient switching (pre-converter sensor, left bank). What does this mean exactly? Ive checked the other threads related to this, and I noticed the cats were mentioned. Only problem is I have none, and Nelson Performance adjusted the tune accordingly. Any suggestions as to what is causing this? Many thanks.

bank 1 sensor 1 O2 sensor is up stream of the cats driveside,,,you having no cats leads me to believe that the driver side O2 sensor is damaged...or the connections to it are ...

swap the driver side O2 with the passenger side see if the code moves if so it is just the O2 sensor..

many of these vehicles have had O2 wiring issues driver side ,,,very hard to access this side..

this operation [no cats]is illegal and you are lucky the dealership did not report you...if this is a registered for road use...

[ukrkoz]

you sure it's not p0133?
http://www.obd-codes.com/p0133

[03BlackBeast]

I just checked this morning, and made sure it is P1133.

[ukrkoz]

some help from other sites

P1133 - Heated Oxygen Sensor (HO2S) Insufficient Switching Bank 1 Sensor
You will need to check the output signal from this O2 sensor, if the voltage low (.10-.25 volts) try spraying propane into the air cleaner to see if the O2 volts go up, it should go to around .75 volts, if nothing happens then the O2 sensor is bad, bank #1 O2 is on the same side as #1 cylinder

Check the connections to the four O2 sensors first to make certain they are not corroded. There is no way to tell which sensor is bad by the code. You need a scan tool to monitor the individual voltages to know which is bad. This falls into the category of take it to the dealer which may not be a bad idea. The O2 sensors are covered under warranty. My Vette, a 2003 Z06 just had one of the catalytic converters replaced under warranty. Warranty on emissions for 2003 year cars is 8 years from delivery or 80,000 miles. It doesn't matter if you are the original owner or not, it is still covered. Newer model cars are covered for ten years or 100,000 miles. I don't recall the year the length of warranty changed.

and they say that your o2 sensors still might be under warranty
http://www.epa.gov/obd/warranties.htm

[03BlackBeast]

Would it be a bad idea to just replace the sensor when I got to my muffler guy? Exhaust has to be redone because it'll be cut off for my lift kit. Thanks for the information.

[J-Ri]

That's what I would do, if you've got over 100k miles on it they should be replaced anyway, plus that code almost has to be a bad sensor. If the voltage was high/low there would be a code for that, so that rules out a bad connection, low switching (from what I have seen) is always the sensor. Have both upstream sensors replaced, having one new and one old one can cause a slight power imbalance between the banks that can cause it to run worse than with two old sensors.

[03BlackBeast]

Actually, how difficult would this be to do myself? I'm askin now cause I haven't had a chance to go look and find them. Again, thanks for the help and quick responses

[mno221]

I have a 2001 Silverado 5.3, i was getting the 071and 074 codes then the 1133 pop up, clear the codes and the 1133 came back. Changed out both oxygen sensors but the P1133 still came back. What can be the problem?

[j cAT]

Originally Posted by mno221

I have a 2001 Silverado 5.3, i was getting the 071and 074 codes then the 1133 pop up, clear the codes and the 1133 came back. Changed out both oxygen sensors but the P1133 still came back. What can be the problem?

if after replacing the upstream O2 sensors you get the p1133 code this means you somehow damaged the wire/connector to the upstream sensor or the O2 sensor is defective on the driverside.

another failure would be the fuel regulator is leaking. intake manifold vac leak. see if you have the proper fuel pressure and the pressure does not rapidly fall off with key on engine off. pull vac line off reg see if fuel comes out or strong smell of fuel.

[mno221]

Originally Posted by j cAT

if after replacing the upstream O2 sensors you get the p1133 code this means you somehow damaged the wire/connector to the upstream sensor or the O2 sensor is defective on the driverside.

another failure would be the fuel regulator is leaking. intake manifold vac leak. see if you have the proper fuel pressure and the pressure does not rapidly fall off with key on engine off. pull vac line off reg see if fuel comes out or strong smell of fuel.

Thanks, I'll check everything again tomorrow. I also replace the fuel regulator last month.

[4x4junkie]

DTC P1133 HO2S Insufficient Switching Bank 1 Sensor 1 w/o RPO OSG






Circuit Description
The powertrain control module (PCM) monitors the heated oxygen sensor (HO2S) activity for 100 seconds. During this monitor period, the PCM counts the number of times that the HO2S switches from rich to lean and lean to rich. A DTC P1133 sets when the PCM determines that the HO2S did not switch enough times.
A lean to rich switch is determined when the HO2S voltage changes from less than 300 mV to more than 600 mV. A rich to lean switch is determined when the HO2S voltage changes from more than 600 mV to less than 300 mV.
Conditions for Running the DTC
No active mass air flow (MAF) DTCs
No active intake air temperature (IAT) DTCs
No active engine coolant temperature (ECT) DTCs
No active throttle position (TP) DTCs
No active Injector DTCs
No active crankshaft position (CKP) sensor DTCs
No active ignition control (IC) DTCs
The fuel system is operating in Closed Loop.
The engine run time is more than 120 seconds.
The engine speed is between 1,200 RPM and 3,000 RPM.
The ignition voltage is more than 9 volts.
The ECT is more than 65°C (149°F).
The MAF is between 23 g/s and 50 g/s.
The evaporative emission (EVAP) purge duty cycle is more than 0 percent.
Conditions for Setting the DTC
The PCM determines that within 100 seconds the HO2S lean to rich switches are less than 10 and rich to lean switches are less then 10.
Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL and the DTC.
Diagnostic Aids
Important

Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
Inspect the HO2S signal circuit for being shorted to a PCM ground. The HO2S signal circuit shorted to a PCM ground sets a switching DTC.
A malfunction in the HO2S heater circuits will cause a DTC P1133 to set. Check HO2S heater circuits for intermittent opens or loose connections.
An oxygen supply inside the HO2S is necessary for proper operation. This supply of oxygen is provided through the HO2S wires. All HO2S wires and connections should be inspected for breaks or contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Wiring Systems.
Using the Freeze Frame and Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame and Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass or a fail. Operate vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature etc., that you observed. This will isolate when the DTC failed.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.

1. This step determines if the fault is present. This test may take 5 minutes for the diagnostic to run. For any test that requires probing the PCM or a component harness connector, use the connector test adapter kit . Using this kit prevents damage to the harness connector terminals.
2. When DTCs P1133 and P1153 are set at the same time, this is a good indication that a fuel contamination condition is present.
3. An exhaust leak 6-12 inches away from the HO2S can cause a DTC to set.
4. This step tests the HO2S for being tight and the connectors and circuits are OK.
5. This step tests the integrity of the HO2S low signal circuit to the PCM.
6. This step tests the integrity of the signal circuit to the PCM.
7. Certain room temperature vulcanizing (RTV) silicon gasket materials give off vapors that can contaminate the HO2S. There is also a possibility of silicon contamination caused by silicon in the fuel. If the sensors appear to be contaminated by silicon and all the silicon sealant is a non-silicon base, advise the customer to try a different fuel company. A missing fuel filler restrictor indicates the customer may have used leaded fuel.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--
Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important

If any DTCs are set, except P1153, refer to those DTCs before proceeding with this diagnostic table.

1. Install a scan tool.
   
2. Idle the engine at the normal operating temperature.
   
3. Operate the vehicle within the parameters specified under the Conditions for Running the DTC in the supporting text.
   
4. Monitor the DTC Information using the scan tool. Refer to Using Connector Test Adapters in Wiring Systems.

Did DTC P1133 fail this ignition?

--
Go to Step 3
Go to Diagnostic Aids

3

Did DTC P1153 also fail this ignition?

--
Go to Step 8
Go to Step 4

4

1. Inspect for an exhaust system leak. Refer to Exhaust System Inspection in Engine Exhaust. After you inspect the exhaust system, return to this diagnostic.
   
2. If you find an exhaust leak, repair the exhaust leak as necessary.

Did you isolate an exhaust leak?

--
Go to Step 14
Go to Step 5

5

Visually and physically inspect the following items:
Ensure that the HO2S is securely installed.
Inspect for corrosion on the terminals.
Inspect the terminal tension at the HO2S and at the PCM.
Inspect for damaged wiring.
Did you find and correct the condition?

--
Go to Step 14
Go to Step 6

6

1. Disconnect the HO2S.
   
2. Jumper the HO2S low circuit, PCM side, to a known good ground.
   
3. Monitor the HO2S voltage on the Engine 1 Data List using the scan tool.

Does the scan tool indicate a voltage within the specified range?

350-550 mV
Go to Step 7
Go to Step 10

7

1. Jumper the HO2S high and low, PCM side, signal circuits to a battery ground.
   
2. Monitor the HO2S voltage using the scan tool.

Does the scan tool indicate a voltage below the specified value?

200 mV
Go to Step 13
Go to Step 9

8

Important

Determine and correct the cause of the contamination before replacing a sensor. Inspect for the following conditions:
Fuel contamination
Use of improper RTV sealant
Engine oil consumption
Coolant consumption
Replace the affected heated oxygen sensor (H20S). Refer to Heated Oxygen Sensor (HO2S) Replacement - Bank 1 or Heated Oxygen Sensor (HO2S) Replacement - Bank 2 .
Is the action complete?

--
Go to Step 14
--

9

1. Remove the jumper wire from the HO2S low circuit.
   
2. Measure the voltage from the HO2S low signal circuit to a battery ground using the DMM . Refer to Measuring Voltage in Wiring Systems.

Does the DMM indicate a voltage near the specified value?

5 V
Go to Step 12
Go to Step 11

10

Repair the high signal circuit for a short to ground or a short to voltage. Refer to Wiring Repairs in Wiring Systems.
Is the action complete?

--
Go to Step 14
--

11

Repair the open HO2S low circuit, or repair the faulty PCM connections. Refer to Wiring Repairs in Wiring Systems.
Is the action complete?

--
Go to Step 14
--

12

Repair the HO2S high signal circuit for an open, or repair the faulty PCM connections. Refer to Wiring Repairs in Wiring Systems.
Is the action complete?

--
Go to Step 14
--

13

Replace the HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement - Bank 1 .
Is the action complete?

--
Go to Step 14
--

14

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
   
2. Idle the engine at the normal operating temperature.
   
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
   
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--
Go to Step 15
Go to Step 2

15

Select the Capture Info option and the Review Info option using the scan tool.
Does the scan tool display any DTCs that you have not diagnosed?

--
Go to the applicable DTC table
System OK

" name=forward
Document ID# 546871
2000 Chevrolet/Geo Chevy K Silverado - 4WD

[4x4junkie]

" name=forward
Document ID# 840348
2003 Chevrolet Chevy C Silverado - 2WD




DTC P1133 or P1153

Circuit Description
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The powertrain control module (PCM) supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started the PCM operates in open loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and closed loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream; low HO2S voltage indicates a lean exhaust stream. This diagnostic will only run once per ignition cycle. The PCM monitors the number of rich-to-lean and lean-to-rich transitions. A transition is defined as, the HO2S voltage changes from above 625 mV to below 250 mV or from below 250 mV to above 625 mV. If the PCM detects that the number of transitions were less than a specified value, DTCs P1133 or P1153 will set.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0220, P0300, P0442, P0446, P0452, P0453, P0455, P0496, P1125, P1258, P1514, P1515, P1516, P1518, P2108, P2135 are not set.
The ECT Sensor parameter is more than 65°C (149°F).
The EVAP Purge Solenoid Command parameter is more than 1 percent.
The MAF Sensor parameter is between 23-50 g/s.
The Engine Speed parameter is between 1,200-3,000 RPM.
The TP Indicated Angle parameter is 5 percent more than the value observed at idle.
The Loop Status parameter is closed.
The Ignition 1 Signal parameter is between 10-18 volts.
The Fuel Tank Level Remaining parameter is more than 10 percent.
The Engine Run Time parameter is more than 160 seconds.
The above conditions are met for 50 seconds.
Conditions for Setting the DTC
The PCM detects that the affected HO2S lean-to-rich or rich-to-lean transitions are less than a calibrated 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.
Test Description
The number below refers to the step number on the diagnostic table.

1. If the voltage is varying above and below the specified value, the condition is not present.

Step

Action

Value(s)

Yes

No

Schematic Reference:

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

1. Start the engine.
   
2. Allow the engine to reach operating temperature. Refer to Scan Tool Data List .
   
3. Operate the engine at 1,500 RPM for 30 seconds.
   
4. Observe the affected HO2S voltage parameter with a scan tool.

Is the HO2S voltage parameter varying above and below the specified range?

250-625 mV
Go to Step 3
Go to Step 4

3

1. Observe the Freeze Frame/Failure Records for this DTC.
   
2. Turn OFF the ignition for 30 seconds.
   
3. Start the engine.
   
4. 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 4
Go to Intermittent Conditions

4

1. Turn OFF the ignition.
   
2. Disconnect the affected HO2S.
   
3. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and a good ground.
   
4. Turn ON the ignition, with the engine OFF.
   
5. Observe the HO2S voltage parameter with a scan tool.

Is the HO2S voltage parameter less than the specified value?

100 mV
Go to Step 6
Go to Step 5

5

Test the HO2S high signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

--
Go to Step 12
Go to Step 9

6

1. Remove the jumper wire from the previous step.
   
2. Connect a 3-amp fused jumper wire between the high signal circuit of the HO2S harness connector on the engine harness side and the low signal circuit of the HO2S harness connector on the engine harness side.
   
3. Observe the HO2S voltage parameter with a scan tool.

Is the HO2S voltage parameter less than the specified value?

100 mV
Go to Step 8
Go to Step 7

7

Test the HO2S low signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

--
Go to Step 12
Go to Step 9

8

Test for an intermittent and for a poor connection at the HO2S. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?

--
Go to Step 12
Go to Step 10

9

Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?

--
Go to Step 12
Go to Step 11

10

Important

The HO2S may be damaged due to contamination. Prior to replacing the HO2S inspect for the following sources of contamination:
A silicon contaminated HO2S
Fuel contamination--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Engine oil consumption--Refer to Oil Consumption Diagnosis in Engine Mechanical.
Engine coolant consumption--Refer to Loss of Coolant in Engine Cooling.
Replace the affected HO2S. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement?

--
Go to Step 12
--

11

Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?

--
Go to Step 12
--

12

1. Clear the DTCs with a scan tool.
   
2. Turn OFF the ignition for 30 seconds.
   
3. Start the engine.
   
4. 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 13

13

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

" name=forward
Document ID# 840348
2003 Chevrolet Chevy C Silverado - 2WD

[4x4junkie]

that is the gm service manual repair info for a 2003 chevy silverado 4.8L 2wd.. should be comparable to 4wd as well... hope that info helps resolve your issue