The diagnostic code I got was 0901- "Front Right Htd 02 sensor heater". I don't know what this is- can someone tell me in more general terms what this actually is? I know of o2 sensors, etc., which are on my Y, but is this a certain part of an o2 sensor or something? The engine mods I have done so far are a stillen pop charger intake (40k), udp (44k), and Cattman Y (50k). Can any of these have caused the problem? I currently have 56k on my car right now. How hard is this to fix, and how necessary is it to fix immediately? -thanks for all help-

 

DTC 0901

Diagnostic Trouble Code 0901 points to a problem with the Front Heated Oxygen Sensor, Right Bank.

The rightcylinder bank is also called the rear bank. It is cylinders 1,3,5.

The Front Heated Oxygen Sensors are installed in the Y-pipe, the part of the exhaust system which conveys
exhaust gases from the exhaust manifolds to the Catalytic Converter. There is an Oxygen Sensor in each branch
of the Y-pipe. These sensors produce a signal which varies with the concentration of oxygen in the exhaust gas,
as compared to the outside air. This signal is sent to the Engine Control Module which uses it to control the fuel
injection system.

DTC 0901 is detected when the current drawn by the heating element in the Oxygen Sensor is out of the normal
range. Possible causes include ...
- harness or connectors (the sensor circuit is open or shorted.)
- a defective Front Heated Oxygen Sensor (right bank).

The heated Oxygen Sensors have two components: a heating element and a sensing element. The heating
element may be tested with an ordinary ohmmeter. This test is done with the engine off.

Follow the wires away from the Oxygen Sensor until you find the nearest electrical connector. Disconnect the
connector. Viewed with the connector latch at the 12 o'clock position, there are three terminals. They are
numbered 1-3, right to left. Be sure to measure the terminals in the connector half which is attached to the
Oxygen Sensor, not the one which leads to the Engine Control Unit.

Measure the resistance between terminals 1 and 3.
The factory spec is 2.3-4.3 ohms at 77 degrees Fahrenheit.

Measure the resistance between terminals 1 and 2.
The reading should be infinity (no connection).

Measure the resistance between terminals 2 and 3.
The reading should be infinity (no connection).

If the resistance measurements are significantly different from the factory specifications the sensor is faulty and
must be replaced.

If the resistance measurements meet the factory specifications the sensor may be good and the wiring is
defective. You could exchange the two Front Heated Oxygen Sensors and reset the Engine Control Module.
Then drive normally and expect the Malfunction Indicator Lamp to turn on again. If you still get DTC 0901 the
wiring is faulty. If you get DTC 1001 the sensor is bad.
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If you don't replace a faulty O2 sensor your car will not develop full power, suffer from poor fuel mileage and emissions will go up. It is a very easy 20 minute replacement for about $75 or it is more complicated 1 hour replacement for about $35. I'm assuming you fix it yourself and don't bring the car somewhere.