I have error codes p0156 p0161

Here's a link for codes P0446,P0443. https://www.obd-codes.com/p0446 Here's the link for P0403. P0403 Exhaust gas recirculation EGR circuit malfunction Here's code P0135 P0135 OBD II Trouble Code O2 Sensor Heater Circuit Malfunction Bank 1... Here's code P0141 P0141 OBD II Trouble Code O2 Sensor Heater Circuit Malfunction Bank 1... Here's code P0155. P0155 OBD II Trouble Code 02 Sensor Heater Circuit Malfunction Bank 2... Here's the last code.yay P0161. P0161 OBD II Trouble Code HO2S Heater Circuit Malfunction Bank 2 Sensor 2... The last 3 codes might just be one sensor.

P0156 FORD - O2 Sensor Circuit Malfunction Bank 2 Sensor 2
P0156 Ford O2 Sensor Circuit Malfunction Bank 2 Sensor 2

P0161: heater circuit malfunction in secondary 02 in bank 2
P0135 Bank 1 Sensor 1 Heater Performance Problem
P0141: HO2S Heater Performance Bank 1 Sensor 2.
02 sensors and or cat converter is issue

That code means there is a malfunction in the 0/2 sensor circuit of the downstream sensor on bank 2 which is the driver's side. It could be the sensor, and air leak in the Catalytic Converter, the computer or related wiring

did you replace to top intake gasket you removed when you replaced the back spark plugs ,and do you torque it down right

error codes p0156 (02 sensor circuit malfunction) ( bank 2 sensor 2) &
p0161 (02 sensor heater circuit) (bank 2 sensor 2 ) are related. The faulty heater in the sensor will cause the PO156 to set as well. Bank 2 sensor 2
will be located on the drivers side after the converter.

As of 1996,all cars sold in the US were required to have an OBD-II computer interface port.
You may want to go to Advance Auto Parts, AutoZone, or Pep Boys, and get a free read
of the code(s) that you computer may be posting to help with your diagnosis.

The code coming from your vehicle's computer may be one or more of:

P0130 02 Sensor Circuit Malfunction (Bank I Sensor 1)
P0131 02 Sensor Circuit Low Voltage (Bank I Sensor I)
P0132 02 Sensor Circuit High Voltage (Bank I Sensor 1)
P0133 02 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134 02 Sensor Circuit No Activity Detected (Bank I Sensor 1)
P0135 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136 02 Sensor Circuit Malfunction (Bank I Sensor 2)
P0137 02 Sensor Circuit Low Voltage (Bank I Sensor 2)
P0138 02 Sensor Circuit High Voltage (Bank I Sensor 2)
P0139 02 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140 02 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0142 02 Sensor Circuit Malfunction (Bank I Sensor 3)
P0143 02 Sensor Circuit Low Voltage (Bank I Sensor 3)
P0144 02 Sensor Circuit High Voltage (Bank I Sensor 3)
P0145 02 Sensor Circuit Slow Response (Bank 1 Sensor 3)
P0146 02 Sensor Circuit No Activity Detected (Bank I Sensor 3)
P0147 02 Sensor Heater Circuit Malfunction (Bank I Sensor 3)
P0150 02 Sensor Circuit Malfunction (Bank 2 Sensor I)
P0151 02 Sensor Circuit Low Voltage (Bank 2 Sensor I)
P0152 02 Sensor Circuit High Voltage (Bank 2 Sensor 1)
P0153 02 Sensor Circuit Slow Response (Bank 2 Sensor 1)
P0154 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
P0155 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0156 02 Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 02 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 02 Sensor Circuit High Voltage (Bank 2 Sensor 2)
P0159 02 Sensor Circuit Slow Response (Bank 2 Sensor 2)
P0160 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
P0161 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
P0162 02 Sensor Circuit Malfunction (Bank 2 Sensor 3)
P0163 02 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
P0164 02 Sensor Circuit High Voltage (Bank 2 Sensor 3)
P0165 02 Sensor Circuit Slow Response (Bank 2 Sensor 3)
P0166 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
P0167 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)

Note: "Bank 1" is the side of the engine with cylinder 1. "Bank 2" is the other side.

P0300 - Random/Multiple Cylinder misfire detected
P0301 - Cylinder 1 misfire detected
P0302 - Cylinder 2 misfire detected
P0303 - Cylinder 3 misfire detected
P0304 - Cylinder 4 misfire detected
P0305 - Cylinder 5 misfire detected
P0306 - Cylinder 6 misfire detected
P0307 - Cylinder 7 misfire detected
P0308 - Cylinder 8 misfire detected
P0313 - Misfire detected with low fuel

Maximas with the VE30DE and VQ30DE engines use a distributorless ignition system that is controlled by the Engine Control Module (ECM). The ECM receives a signal from the crankshaft sensor (the CPS - Crankshaft Position Sensor), and processes the signal based on inputs
from other various engine sensors, including the Oxygen sensor.
(this is the role of the O2 sensor in ECM operation).
Then the ECM sends signals to each of the individual coils in the proper firing order.
This system is more efficient than a distributor, and has fewer moving parts. The high voltage coils are directly attached to each spark plug, allowing a higher energy spark within the cylinder. A high energy spark means a faster, more thorough burning of the air/fuel mixture, which produces more power and lower emissions.


SECONDARY SPARK TEST - works for all cars, including Maxima.


1. Remove the spark plug.

2. Install the spark plug to the ignition coil/coil pack, then attach the coil wiring.

3. Ground the plug at a good ground location on the engine.

4. Crank the engine and check for spark.

5. If spark occurs, the ignition system is functioning properly.

6. If no spark exists, test the ignition coil/coil pack, power transistor and related wiring.

----------------------------------------------------------------------------------------------------------------------------
HEI Ignition Spark test - works for all cars, including Maxima.

The next level test you may want to try is a HEI (high energy ignition) spark tester kit. Cost is
about $30 at most auto parts stores. Harbor Freight Tools sells a chinese equivalent for about $16.
Place the spark tester on each of the spark plugs, and watch as the little light in the tester will
light up each time the spark plug is fired by the computer. You can actually see weak or
intermittent sparking as the motor runs - you can tell by the relative strength of the light as
you compare the intensity and duration of the light across all 6 cylinders.

If your problem were the alternator (or its built-in voltage regulator), your battery would not be
getting a proper charge, and you
wouldn't be able to start the car after a drive, since the battery would have been drained during the
drive - normally, the alternator will both charge the battery and run all electrical
features of the car during a drive.

To test your alternator, place your DMM (digital multimeter) across the battery terminals while the
car is running - it should read 13.5VDC to 14.5VDC. With the car off, you can test your battery
voltage with the same DMM - it should read 12.65 VDC (for a fully charged battery).

Alternatively, you can take your car to Advance Auto Parts, AutoZone, or Pep Boys, and they'll
attach their "charging system tester" to your car and give your car a nice test for free.
I do this with my customers' cars just to get that nifty printout of the problem. Its nice
to show a vehicle owner somethng in black & white when I'm recommending a new charging
or ignition system component (some of which can be a bit pricey).

P0804 is the highest OBD-II trouble code.

Here's your Oxygen sensor codes.

P0130 02 Sensor Circuit Malfunction (Bank I Sensor 1)
P0131 02 Sensor Circuit Low Voltage (Bank I Sensor I)
P0132 02 Sensor Circuit High Voltage (Bank I Sensor 1)
P0133 02 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134 02 Sensor Circuit No Activity Detected (Bank I Sensor 1)
P0135 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136 02 Sensor Circuit Malfunction (Bank I Sensor 2)
P0137 02 Sensor Circuit Low Voltage (Bank I Sensor 2)
P0138 02 Sensor Circuit High Voltage (Bank I Sensor 2)
P0139 02 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140 02 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0142 02 Sensor Circuit Malfunction (Bank I Sensor 3)
P0143 02 Sensor Circuit Low Voltage (Bank I Sensor 3)
P0144 02 Sensor Circuit High Voltage (Bank I Sensor 3)
P0145 02 Sensor Circuit Slow Response (Bank 1 Sensor 3)
P0146 02 Sensor Circuit No Activity Detected (Bank I Sensor 3)
P0147 02 Sensor Heater Circuit Malfunction (Bank I Sensor 3)
P0150 02 Sensor Circuit Malfunction (Bank 2 Sensor I)
P0151 02 Sensor Circuit Low Voltage (Bank 2 Sensor I)
P0152 02 Sensor Circuit High Voltage (Bank 2 Sensor 1)
P0153 02 Sensor Circuit Slow Response (Bank 2 Sensor 1)
P0154 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
P0155 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0156 02 Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 02 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 02 Sensor Circuit High Voltage (Bank 2 Sensor 2)
P0159 02 Sensor Circuit Slow Response (Bank 2 Sensor 2)
P0160 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
P0161 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
P0162 02 Sensor Circuit Malfunction (Bank 2 Sensor 3)
P0163 02 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
P0164 02 Sensor Circuit High Voltage (Bank 2 Sensor 3)
P0165 02 Sensor Circuit Slow Response (Bank 2 Sensor 3)
P0166 02 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
P0167 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)

Note: "Bank 1" is the side of the engine with cylinder 1. "Bank 2" is the other side.

P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1).

Potential Symptoms: You will likely notice poor fuel economy the illumination of the MIL.

Causes: A code P0155 may mean that one or more of the following has happened:
O2 Heater element resistance is high
Internal short or open in the heater element
O2 heater circuit wiring high resistance
open or short to ground in the wiring harness

Possible Solutions:
Repair short or open or high resistance in wiring harness or harness connectors
Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)



P0156 - 02 Sensor Circuit Malfunction (Bank 2 Sensor 2)
The o2 (oxygen) sensors measure oxygen content in the exhaust. The PCM (powertrain control module) then uses this information to regulate fuel injector pulse. The o2 sensors are very important for the proper operation of the engine. Innacurate or faulty o2 sensors can cause the PCM to add or take away fuel based on the faulty o2 sensor voltage which can cause a host of problems.

A P0156 code refers to the Bank 2,2 o2 sensor or the downstream (post-cat) o2 sensor on Bank 2. It is a four wire sensor. The PCM supplies a ground circuit and a reference voltage circuit of about 0.5 volts. Also for the o2 sensor heater element there is a battery voltage supply wire and another ground circuit for that. The o2 sensor heater allows the o2 sensor to warm up faster, thus achieving closed loop in less time than it would normally take for the exhaust to warm the sensor up to operating temperature. The O2 sensor varies the supplied reference voltage based on oxygen content in the exhaust. It is capable of varying from about 0.1 to 0.9 volts, 0.1 V indicating lean exhaust and 0.9 V indicating rich exhaust. This P0156 code indicates that the Bank 2, 2 o2 sensor is stuck low for too long or isn\'t active at all.

Symptoms: Often post-cat o2 sensor problems present few symptoms since they are inputs to the PCM to monitor catalytic converter quality and don\'t directly control fuel. sometimes no symptoms are noticeable. However the following may be possible on some vehicles:
MIL (Malfunction Indicator Lamp) illumination
Decrease in MPG
Increase in tailpipe emissions

Causes: Potential causes of an P0156 code include:
Bad O2 sensor
Signal shorted to voltage
Wiring problems due to contact with exhaust components
Holes in exhaust near o2 sensor

Possible Solutions:
If you have access to a scan tool, check the signal voltage for the Bank 2,2 oxygen sensor with the engine at normal operating temperature. Is it stuck low currently? If so, increase RPM for a few seconds and see if it affects the reading. If it begins working with increased RPM, check for holes in the exhaust near the o2 sensor that may cause a false lean. If the exhaust pipe is intact, the sensor is sluggish, replace it.

If the Bank 2,2 o2 sensor voltage reading remains low with increased RPM, unplug it and then observe the reading. It should have increased to about 0.5 volts or thereabouts. If it did, check for water intrusion or other connector problems. If none are found, replace the shorted o2 sensor. If the voltage reading is still stuck low after unplugging the sensor, then suspect a wiring problem. Using a voltmeter, with the o2 sensor unplugged, check for voltage on the signal circuit at the o2 sensor connector(PCM side). It can vary with model, but should be about 0.5 volts and not above 1 volt. If the voltage reading is too high, repair short to voltage on signal circuit. If the signal voltage checks out, suspect the PCM.


Hope this helps (remember to rate this answer).

BANK ONE IS THE REAR BANK OF CYLINDERS AND TWO THE FRONT BANK