Catalytic converter

[albertothe16]

I HAVE A 05 LEGACY i and I have a code P0420 code for Catalytic Converter Below Threshold Bank 1 and a P0137 02 Sensor Low voltage Bank 1 sensor 2. I've been looking for a new Cat to replace mine but the OEM is too expensive and most of the Cat that I find online cannot be shipped to New York. Does anybody knows which Catalytic should I buy? any recommendation?

[blackobxt]

I’d start with the oxygen sensors first. If you have one handy, use a scan tool to monitor the front and rear o2 sensors and see what they are doing

[Marvick08GT]

Because you have another code referencing the second O2 sensor, replace that one first. Then you can monitor and see if it is working.

 

If the second O2 is malfunctioning or shorted, it would definitely cause the p0420 to show up.

[Max Capacity]

I assume this is on a 2.5i engine ?

 

Bank 1 sensor 2, is there a O2 sensor on the drivers side on a 2.5i ?

[Marvick08GT]

B1 S1 is the primary A/F

B1 S2 is the secondary O2

 

This is from what I remember when a racoon chewed through my second O2 sensor

 

When there is only 1 bank it is B1 regardless of the side. When 6 or 8cyl B1 is the drivers side and B2 is the passenger. (For most cars, there are some weirdos out there! )

[Max Capacity]

Here's the list of CEL codes,

 

https://legacygt.com/forums/showthread.php/trouble-codes-cels-26113.html

 

 

P0137 is the rear O2 sensor.

 

The confusion comes from the fact that GT's have a Front O2, (bank 1) under the passenger side head in the exhaust manifold. Bank 1 is also where cylinders 1 & 3 are, which is the passenger side of the car.

 

Bank 2 on a GT is the rear sensor in the downpipe.