P0137 --Help--

[a4aspeed3]

Hey everyone im new to this forum. I have a 2007 mazdaspeed3 and have the the code p0137 i replaced the o2 sensor and erased the check engine light. 20 miles later I got the check engine light on with the same code reading. Please Help emission testing is coming up lol.

My mods are: midpipe, cobb sri,bpv

 

[spdjnke]

ahhhhh? which one of the 02 sensors did you replace...chances are it's the down draft one that needs to be replaced.

 

[a4aspeed3]

I replaced the second sensor right before the midpipe, i tried with and without a fouler and still the same code

 

[spdjnke]

hmmmm thats interesting, since the code is for a rear heated 02 sensor if you've replaced it and still getting the code that means the sensor is out of perimeter. The value at this juncture should be 0.07-0.52V and if it is then you have a short to ground somewhere...check your connections and the wires to ensure there is no break in the junction or melted or kinked wire somewhere.