Is there a way I can fix an OBDII problem on my own?

Question

I took my car to get it inspected today and the emission test failed. It seems like the
P0037 and P0031 which are the Heater Control Circuit Low Bank 1 Sensor 2 and 1 are the problem. I don't know how much this will take to get it fixed. If there is an easy and cheaper way that I can do, please tell me. I don't know much about this but any help and answers are appreciated. Thanks.

P.S.
If you need any more information please let me know.

I took my car to get it inspected today and the emission test failed. It seems like the
P0037 and P0031 which are the Heater Control Circuit Low Bank 1 Sensor 2 and 1 are the problem. I don't know how much this will take to get it fixed. If there is an easy and cheaper way that I can do, please tell me. I don't know much about this but any help and answers are appreciated. Thanks.

P.S.
If you need any more information please let me know.

Make:Subaru
Model:Impreza 2.5rs
Engine:2.5L H4

Answer 1

There are s couple of causes for this. The most likely cause is that the oxygen sensor(s) self-heater circuit has shorted out, causing the heater voltage seen by the computer to go below the expected value. Another possibility could be damaged wiring due to heat, collision damage, etc.
Without the use of a professional level scanner, you are only going to be guessing.
If you have a DIGITAL volt-ohm meter, you can measure both the COLD resistance across the heater connections of the sensor, and you can read the heater voltage while the engine is running. (You will need the wiring diagram to identify the correct wires on the sensor) to be sure where the failure lies.
Many shops wouldn't even go this far, they would read the data stream with the scanner, then depending upon what they saw, would repair as necessary.
If you are the gambling sort, you can purchase ALL the oxygen sensors and replace them. After the replacement, it is important that the codes be CLEARED, then the car must be driven through several drive cycles for the sensors and monitors to be set to "complete" or the emissions test will fail again for "MONITORS INCOMPLETE".
If you are unfamiliar with the drive cycles, then make it a point to drive the car for a minimum of 300 miles making sure to drive in normal traffic, stop and go traffic, cruising around 40 - 45 mph, and some freeway cruising using the cruise control if possible, all avoiding harsh throttle activity.

Good Luck

Answer 2

It is possible but difficult. The fault code is a symptom code. like going to the doctor with a headache. Was it a hangover or anurism. The fault code only give you a system and a symptom.

Answer 3

Make
Model
Engine size

Would be a good thing to know here!