What does P0134 mean?
The oxygen sensor monitors the oxygen content in the vehicle's exhaust gases. It sends a signal to the transmission control module (PCM), which in turn uses the information received to regulate the ratio of fuel and air mixture supplied to the engine cylinders.
When there is insufficient oxygen in the exhaust gases, the vehicle's PCM reduces the amount of fuel used by the engine. This is important because if there is not enough oxygen in the exhaust gases, fuel consumption increases, as well as the amount of harmful substances emitted from the vehicle's exhaust gases.
When there is insufficient fuel, the vehicle's PCM increases the amount of fuel used by the engine. This is also quite important because if there is not enough fuel, hydrocarbons and nitrogen oxides will be released into the atmosphere.
Symptoms of malfunction
The main driver symptom of P0140 is the MIL (Malfunction Indicator Light) illumination. It is also called Check engine or simply “check light”. They can also appear as:
- The Check Engine Light (CEL) or Malfunction Indicator Light (MIL) will illuminate.
- Possible high fuel consumption.
- There is too much smoke coming out of the exhaust pipe.
- There likely won't be any other noticeable problems other than the "Check Engine" on the dashboard.
The reason is this: the oxygen sensor at the rear or after the catalytic converter does not affect the fuel supply. It only measures the efficiency of the catalytic converter. For this reason, you most likely will not notice any problems with the engine.
Causes of error P0134
When the oxygen sensor is working properly, it will give a reading (in millivolts) that fluctuates up and down. If the PCM detects that the sensor readings are not changing, it will store a code P0134. The most common causes of this error are:
- Oxygen sensor heater circuit malfunction
- Loose or damaged electrical wires related to the oxygen sensor
- Corroded oxygen sensor connector
- Worn or damaged vacuum hoses
- Malfunction of the automatic transmission control module (PCM)
How to check a lambda probe with a multimeter
When there are jerks when driving, increased fuel consumption, and a lighted “check”, then it is worth carrying out diagnostics. These signs may indicate other malfunctions, but if you have a multimeter, you can check the oxygen sensor yourself. Experts recommend checking the lambda by measuring voltages.
But before any measurements, you need to warm up the internal combustion engine. If the lambda is cold, it will not work. It is also recommended to remove the sensor, if possible, and inspect it and the wiring for dirt or damage. If the sensor is deformed, the electrode is scratched or covered with soot or carbon deposits, then it is better to replace it.
Heating circuit voltage measurements
Turn on the ignition, pierce the wires that go to the heater with probes. You can also plug multimeter probes into the connector. The voltage will be approximately equal to the voltage in the on-board network. If the engine is not running, then there may be no voltage.
Usually the plus comes directly to the heater. The minus is supplied by the control unit. If there is no positive, you should check the circuits from the battery to the sensor. If there is no minus, then you need to check the circuit from the ECU to the sensor.
Heater check
You can check the functionality of the oxygen sensor using an ohmmeter. Very often the breakdown is associated with the heating coil or the wiring to it.
To check, an ohmmeter is connected between the heater contacts. If the heater is working properly, the ohmmeter will show a resistance of 2 to 10 ohms. In the heating circuit, the resistance will be from 1 kOhm to 10 mOhm. If there is no resistance, then you should look for a break in the wiring.
How does a mechanic diagnose a P0134 code?
First, the mechanic will connect the OBD-II scanner to the vehicle's diagnostic port and read all stored data and error codes to determine when and under what circumstances the P0134 code occurred. He will then clear the error codes from the computer's memory and test drive the car.
To determine if the P0134 code appears again, the vehicle must reach normal operating temperature. If the error code appears again, a mechanic will check the electrical wires and oxygen sensor connector for corrosion or damage. The mechanic will also monitor the oxygen sensor readings in real time using a scanner. This will help determine if the sensor is working properly.
If necessary, a mechanic will replace the faulty oxygen sensor. It should be noted that in rare cases, the problem may be a faulty transmission control module (PCM).
On which cars is this problem most common?
The problem with code P0134 can occur on different machines, but there are always statistics on which brands this error occurs more often. Here is a list of some of them:
- Acura (Acura mdx)
- Audi (Audi a6)
- BMW
- Chery (Chery Amulet, Tiggo, Fora)
- Chevrolet (Chevrolet Aveo, Cavalier, Captiva, Cruz, Lanos, Lacetti)
- Chrysler (Chrysler Voyager)
- Citroen (Citroen Berlingo)
- Daewoo (Daewoo Nexia)
- Dodge (Dodge Durango, Caravan, Neon, Stratus)
- Ford
- Geely
- Honda (Honda Accord, SRV, Stream, Civic)
- Hover
- Hyundai (Hyundai Accent, Getz, Santa Fe, Solaris, Tucson, Elantra)
- Kia (Kia Rio, Sid, Sportage, Cerato)
- Lifan
- Mazda (Mazda 3, Mazda 323, Mazda 6, Mazda cx7, Demio)
- Mercedes (Mercedes w204)
- Mitsubishi (Mitsubishi Outlander, Galant, Lancer, Pajero)
- Nissan (Nissan Almera, Qashqai, Maxima, Note, Pathfinder, Primera, Teana, Tiida)
- Opel (Opel Antara, Astra, Corsa)
- Peugeot (Peugeot 206, 307, Partner)
- Saab 9-5
- Skoda (Skoda Octavia, Fabia)
- Subaru (Subaru Outback, Forester)
- Suzuki (Suzuki Grand Vitara, Liana, Swift)
- Toyota (Toyota Avensis, Corolla)
- Volkswagen (Volkswagen Golf, Passat)
- Volvo (Volvo xc90)
- VAZ 2104, 2107, 2110, 2112, 2114, 2115
- Gazelle Business, umz 4216
- Zaz Chance
- Lada Vesta, Granta, Kalina, Niva, Priora
- UAZ Patriot
With fault code P0134, you can sometimes encounter other errors. The most common ones are: P0030, P0053, P0112, P0130, P0131, P0132, P0135, P0137, P0138, P0154, P0155, P0171, P0172, P0301, P1135, P1496, P2243.
What repairs can fix the P0134 code?
To resolve this error you may need to:
- Check for the error code using a scan tool, clear the code from your computer's memory, and test drive the vehicle to see if the P0134 error code appears again and the Check Engine light comes on.
- Repair or replacement of electrical wires or oxygen sensor connector
- Replacing a faulty oxygen sensor
- Check and, if necessary, repair or replace the exhaust pipe or oxygen sensor heater fuse
Replacing the lambda probe
In most cases, a part such as a lambda probe cannot be repaired, as evidenced by statements about the impossibility of repair from many automobile manufacturers. However, the inflated cost of such a unit from official dealers discourages anyone from purchasing it. The optimal way out of this situation could be a universal sensor, which costs much less than its native analogue and is suitable for almost all car brands. Also, as an alternative, you can purchase a used sensor, but with a warranty period, or a completely exhaust manifold with a lambda probe installed in it.
However, there are cases when the lambda probe operates with a certain error due to severe contamination as a result of combustion products deposited on it. In order to make sure that this is really the case, the sensor must be checked by specialists. After the lambda probe has been checked and its full functionality has been confirmed, it must be removed, cleaned and reinstalled.
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In order to dismantle the oxygen level sensor, it is necessary to warm its surface to 50 degrees. After removal, the protective cap is removed from it and only after that you can start cleaning. It is recommended to use phosphoric acid as a highly effective cleaning agent, which can easily cope with even the most stubborn flammable deposits. At the end of the soaking procedure, the lambda probe is rinsed in clean water, thoroughly dried and installed in place. At the same time, do not forget about lubricating the threads with a special sealant, which will ensure complete tightness.
The structure of a car is very complex, so it needs constant maintenance and timely preventative maintenance. Therefore, if there is a suspicion that the lambda probe is faulty, it is necessary to immediately diagnose its performance and, if the fact of failure is confirmed, replace the lambda probe. Thus, all the most important functions of the vehicle will be maintained at the same level, which will guarantee the absence of further problems with the engine and other important elements of the car.
Replacement problems
When replacing, the old sensor may stick to the pipe. In this case, proceed like this:
- Apply wd-40 generously and try to unscrew
- Turn on the engine, heat the exhaust system and unscrew the sensor
- We try to heat (being careful) the sensor itself and unscrew it
- Tap lightly with a hammer and try to unscrew it again
- If that doesn't help, try thermal shock. Pour cold water onto the well-heated sensor. Try unscrewing it again.
Oxygen sensor price
The price of an oxygen sensor will vary by region and model. It ranges from 1000 to 3000 rubles . Buy a lambda probe in specialized stores and only with a guarantee.
Additional comments for troubleshooting P0134
Although the most common cause of the P0134 code is a faulty oxygen sensor, before replacing the sensor, you must perform a thorough diagnosis and consider all possible causes of the error. First of all, you need to check the electrical wires and the oxygen sensor connector.
Each time after repair work is performed, it is necessary to clear the error codes from the computer's memory and test drive the vehicle to find out if the P0134 error appears again. This will help determine if the problem is resolved.
If during the diagnosis it turns out that everything is in order with the oxygen sensor, as well as the corresponding electrical wires and connector, it is necessary to check the exhaust pipe and the sensor heater fuse.
It should be noted that in rare cases, the problem may be a faulty transmission control module (PCM).
Common causes of violation
Error P0134 does not occur very often. There are few probable reasons for the occurrence of such a violation, and they all indicate an incorrect signal from a specific sensor. Based on this, you can determine the most popular options for the occurrence of error P0134:
- Presence of a short circuit;
- Oxygen sensor malfunction;
- Broken wires and oxidation of contacts.
During diagnostics using special equipment, the causes of the malfunction are identified quite quickly and accurately. In most cases, this violation is provoked by a breakdown of the oxygen sensor and in 5% of them the malfunction is directly related to a short circuit, an open circuit and the presence of oxidation processes in the contacts.
In situations where, along with the error in question, the presence of errors with code P0171 is also displayed, we can conclude that there is a possibility of a break or short circuit. The second error in most cases appears when the air-fuel mixture entering the engine is too lean. It is often accompanied by error code P0134, since in the exhaust circuit the first oxygen sensor is directly responsible for the supply. When the information supply stops, the ECU spontaneously reduces the fuel consumption. Thus, the air-fuel mixture becomes lean.
