Hey guys
Used a little race fuel for an autocross and after last fillup got two current codes..one I could not find.

BO-RFA c2120 can't find this one.

pcm p1133 = HO2S insufficient switching... I'm assuming this is on O2 sensor but ?????

I did check the gas cap and it was tight...

thanks

Jeremy

 

Yep, I made the mistake of putting just 1/4 of a tank of this race mix 103 or so octane since I won a tank full for a great reaction time. I already had a 1/4 of a tank of 93 in there to mix it up.
Unfortunately I found out that it damages the O2 sensors! I had to replace one for a similar code which kept coming back even after a Techron additive and a fresh tankful of Chevron. Most likely I believe you are looking at a purchase of a new O2 sensor I'm sorry to say.
Check w/ Gene at www.GMpartshouse.com for the best pricing vs your local auto store.

 

I have cleared and not come back yet..

can you tell which O2 sensor tripped the code??

anyone know what the other one means??

 

C2120- TPM System Malfunction.Tire pressure moniter system.

 

Jeremy, here u go buddy. This is courtesy of Bill Dearborn aka "the man" from a prior post of his on this code, :

It is the left side front sensor. Here is the Service Manual info for that fault code:

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 600 mV to below 300 mV or from below 300 mV to above 600 mV. If the PCM detects that the number of transitions were less than a specified value, DTC P1133 or P1153 sets.

Conditions for Running the DTC
• DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.
• The Loop Status parameter is Closed.
• The Engine Run Time parameter is more than 160 seconds.
• The Engine Speed parameter is between 1,000-2,300 RPM.
• The Ignition 1 Signal parameter is between 9-18 volts.
• The ECT sensor parameter is more than 50°C (122°F).
• The EVAP purge solenoid command parameter is more than 0 percent.
• The MAF sensor parameter is between 18-50 g/s.
• The TP indicated angle parameter is 5 percent more than the value observed at idle.
• The fuel level parameter is more than 10 percent.
• The above conditions are met for 60 seconds.

Conditions for Setting the DTC
The affected HO2S lean to rich or rich to lean switches are less than a calibrated amount.

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 numbers below refer to the step numbers on the diagnostic table.
3. When DTCs P1133 and P1153 are set at the same time, a fuel contamination condition is present.
4. An exhaust leak 6-12 inches from the HO2S can cause a DTC to set.
5. This step verifies whether a good ground circuit is available.
6. This step verifies the integrity of the signal circuit to the PCM.
7. This step verifies the integrity of the signal circuit to the PCM.

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 except DTC P1133 or P1153 are set, refer to those DTCs before proceeding with this diagnostic table.
1. Install a scan tool.
2. Start the engine and idle the engine at the normal operating temperature.
3. Operate the vehicle within the parameters specified in Conditions for Running the DTC in the supporting text.
4. Use the scan tool in order to monitor the DTC information.
Did DTC P1133 or P1153 fail this ignition? -- Go to Step 3
Go to Intermittent Conditions

3
Did both DTC P1133 and P1153 fail this ignition? -- Go to Step 8
Go to Step 4

4
1. Inspect for an exhaust system leak. Refer to Exhaust Leakage in Engine Exhaust.
2. If you find an exhaust leak, repair the exhaust leak as necessary.
Did you find and correct the condition? -- Go to Step 14
Go to Step 5

5
Inspect the following items:
• Verify 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 signal circuit on the PCM side to a known good ground.
3. Use the scan tool in order to monitor the HO2S voltage on the Engine 1 Data List.
Is the voltage within the specified range? 350-550 mV Go to Step 7
Go to Step 10

7
1. Jumper the HO2S high and low signal circuits on the PCM side to a battery ground.
2. Use the scan tool in order to monitor the HO2S voltage.
Is the voltage less than 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 Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
• Use of an improper RTV sealant
• Engine oil or coolant consumption Refer to Oil Consumption Diagnosis in Engine Mechanical-5.7L.
Replace the affected heated oxygen sensor. Refer to Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 and/or Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 .
Did you complete the replacement? -- Go to Step 14
--
9
1. Remove the jumper wire from the HO2S low signal circuit.
2. Use the DMM in order to measure the voltage from the HO2S low signal circuit to a battery ground. Refer to Measuring Voltage in Wiring Systems.
Is the voltage near the specified value? 5 V Go to Step 12
Go to Step 11

10
Repair the HO2S high signal circuit for a short to ground or for a short to voltage. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair? -- Go to Step 14
--
11
Repair the open in the HO2S low signal circuit, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair? -- Go to Step 14
--
12
Repair the HO2S high signal circuit for an open, or repair the poor PCM connections. Refer to Wiring Repairs in Wiring Systems .
Did you complete the repair? -- Go to Step 14
--
13
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 14
--
14
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 15

15
Observe the Capture Info with the scan tool.
Are there any DTCs that have not been diagnosed? -- Go to Diagnostic Trouble Code (DTC) List
System OK

Bill



You should be able to jack the car up and put her on stands, then buy a o2 sensor socket from a local auto store which will allow you to remove the bad one and replace it yourself. Total cost for the part is probably about $50 from gmpartshouse, vs your local auto store.

Let me know how u do!