Where is the O2 sensor on a 1998 jetta k2. getting a "bank 1 sensor 1" code. Is there more than one sensor? Also, can a misfire in cylinder 3 cause the O2 sensor to malfunction?

P0134 - O2 Sensor Circuit No Activity Detected Sensor 1 Bank 1
P0135 - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
P0053 - O2 Heater Resistance Bank 1 Sensor 1
P0030 - O2 Heater Control Circuit Bank 1 Sensor 1
You need to replace the O2 Sensor Bank 1 Sensor 1
Carquest can help you get the correct part and help you locate it.

The code P0135 means O2 sensor heater circuit malfunction bank 1 sensor 1. This means you most likely have a bad O2 sensor. The possible causes are:

TT - Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Engine Control Module (ECM) Usually the code indicates a bad Oxygen sensor, but an intake vacuum leak or a failing fuel pump can cause the code, so check your intake vacuum hose for a leak or hole. But most likely, you have a faulty Oxygen sensor. Now Bank 1 Sensor 1 means the bad O2 sensor is the one on the number one cylinder side (which is the cylinder closest to the timing belt or where all your belts and pulleys are),which is bank one. If you look really closely, you will see that the number 1 cylinder is just a little bit closer to the belts than the number 2 cylinder. Now that you know which side you are dealing with, the next step is which sensor. There are two O2 sensors on each side (upstream or downstream), four total. Sensor 1 is the upstream sensor, which is before the catalytic converter closest to the exhaust manifold. Number 2 sensor is on or after the catalytic converter. So in short, you are replacing the O2 sensor on the Number 1 cylinder side before the catalytic converter. They are a pain to remove. Get some Pb Blaster lubricating oil and spray on the threads and let sit for 10 minutes and spray it again. You will need a 7/8 Oxygen sensor removal socket to remove it. Don't forget to disconnect negative battery terminal and O2 wire harness first.. Any questions please feel free to email me. Good luck.

both are o2 sensor problems and should be related to each other p0151 -o2 senson malfunction bank 2 sensor 1[ which would be the sensor on the no.2 cylinder side ---before the cat conveter --the p1153 o2 bank 2 sensor1 insuffent switching --its the same o2 sensor -check the wiring and connection if good- than replacement of the o2 sensor is dvised

Reset error codes by disconnecting battery for 5 minutes. Start fresh. all codes should be clear now. drive and see if any new codes come on. They are the ones you need to address.

P0141....O2 Sensor Heater Circuit (Bank 1 Sensor 2)

P0142....O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)

P0143....O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)

P0144....O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)

P0145....O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)

P0146....O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)

P0147....O2 Sensor Heater Circuit (Bank 1 Sensor 3)

P0340....Camshaft Position Sensor 'A' Circuit (Bank 1 or Single Sensor)

Possible O2 sensors:

P2270 O2 Sensor Signal Stuck Lean Bank 1 Sensor 2
P2271 O2 Sensor Signal Stuck Rich Bank 1 Sensor 2
P2272 O2 Sensor Signal Stuck Lean Bank 2 Sensor 2
P2273 O2 Sensor Signal Stuck Rich Bank 2 Sensor 2
P2274 O2 Sensor Signal Stuck Lean Bank 1 Sensor 3
P2275 O2 Sensor Signal Stuck Rich Bank 1 Sensor 3
P2276 O2 Sensor Signal Stuck Lean Bank 2 Sensor 3
P2277 O2 Sensor Signal Stuck Rich Bank 2 Sensor 3
P2278 O2 Sensor Signals Swapped Bank 1 Sensor 3 / Bank 2 Sensor 3
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This is Bank 1 (closer to the dash panel) Sensor 2 (located after the catalytic converter).

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Note: A malfunctioning front oxygen sensor may cause fuel trim codes to set.

1. Several Diagnostic Trouble Codes use specific terminology to refer to sensor location. The illustration and key below explain the following terms:
2. Engine BANK Bank 1 is closer to the dash panel, (also referred to as RH or right hand). Bank 2 is closer to the radiator, (also referred to as LH or left hand).
3. UP Refers to Sensor 1 or "front sensor". It is located closer to the exhaust manifold and before the catalytic converter.
4. DOWN Refers to Sensor 2 or "rear sensor." It is located after the catalytic converter.
5. The following examples show how to interpret oxygen sensor terminology:
6. B1/S1 = Bank 1/Sensor 1 = Dash panel side, BEFORE the catalyst or "upstream"
7. B2/S2 = Bank 2/Sensor 2 = Radiator side, AFTER the catalyst or "downstream"

P0134- O2 sensor Circ, bank 1, Sensor 1 no activity detected

P0135- O2 sensor heater circ, bank 1 sensor 1 malfunction

P0420= Catalyst System Efficiency Below Threshold Bank 1
P0300=Random/Multiple Cylinder Misfire Detected
P0301=Cylinder 1 Misfire Detected
P0172=System Too Rich Bank 1
P2181=Cooling System Performance
you need to write these down,have someone clear the codes in the car,then go for short ride and recheck which if any code reappears.it's like domino's affect,one sensor can start a chain affect with the others.

check the mass air flow sensor there maybe dirt on the filiment inside the sensor causing false readings. cleaning or replacing it may make the codes go away.

You said you changed the O2 sensors, which ones? I do believe that sensor 2 is the Catalyst efficiency monitor, it looks like an O2 but it's function is different. This sensor is behind the Catalytic converter, the O2 is in front. Bank one is the bank that # 1 cylinder is on, so the sensor that is defective is the 2nd sensor back on that sides exhaust pipe.

P0141 - Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 2

P0138 - Heated Oxygen Sensor (HO2S) Circuit High Voltage Bank 1 Sensor 2