I bought a used 2010 Mazda 3 S Sport sedan, and within a week of buying it, my check engine light came on. When I pulled the code, I consistently got a P0431 code, which means that the catalytic converter efficiency is below threshold. The car was running fine, with good acceleration and no stalling or other problems.
Unfortunately, my car could not pass state emissions inspection with the check engine light on, so I had to get this problem fixed. I first took it to a muffler shop, and they told me I needed to replace one of the oxygen sensors, which I did, but that did not solve the problem. Finally I had the converter that is attached to the exhaust manifold replaced, and that got rid of the P0431 code.
I bought a used 2010 Mazda 3 S Sport sedan, and within a week of buying it, my check engine light came on. When I pulled the code, I consistently got a P0431 code, which means that the catalytic converter efficiency is below threshold. The car was running fine, with good acceleration and no stalling or other problems.
Unfortunately, my car could not pass state emissions inspection with the check engine light on, so I had to get this problem fixed. I first took it to a muffler shop, and they told me I needed to replace one of the oxygen sensors, which I did, but that did not solve the problem. Finally I had the converter that is attached to the exhaust manifold replaced, and that got rid of the P0431 code.
- Mark A., Salt Lake City, UT, US