[2one3E90]

2006 N52 6 speed manual

Replaced the top 2 02 sensors with genuine bmw. But got these codes again. Will replacing the bottom downstream 02 sensor fix it? Or am I screwed and need new cats.

[mainbearing]

As mentioned in your other thread, I think the codes are probably real and the converters likely gone bad if the car has no power sometimes. Fake codes should not do that.

[2one3E90]

Originally Posted by mainbearing

As mentioned in your other thread, I think the codes are probably real and the converters likely gone bad if the car has no power sometimes. Fake codes should not do that.

Okay. I dont know wht to do. Get headers with no cats and when its time to smog. Swap headers and clear code. Or buy new n52 cats.

[lowrydr310]

Found this:

https://www.e90post.com/forums/showthread.php?t=1689782

Looks like there might be some hope. Do you have INPA? Check the freeze frame data.

I know mainbearing is right with regard to possible bad cats, but the post-cat sensors are what measure catalyst efficiency so it's still possible that it's the post cat sensors causing it. Check the freeze frame data from the codes.

For what it's worth, the 06 325 I used to have (still in the family so I still maintain it) has 260k miles and burns a quart of oil every 1500 miles and the cats are original.

[2one3E90]

Originally Posted by lowrydr310

Found this:

https://www.e90post.com/forums/showthread.php?t=1689782

Looks like there might be some hope. Do you have INPA? Check the freeze frame data.

I know mainbearing is right with regard to possible bad cats, but the post-cat sensors are what measure catalyst efficiency so it's still possible that it's the post cat sensors causing it. Check the freeze frame data from the codes.

For what it's worth, the 06 325 I used to have (still in the family so I still maintain it) has 260k miles and burns a quart of oil every 1500 miles and the cats are original.

OMG OKAY. Phew. My shop said they can scan the code and see if the 02 sensors are out. Im gonna check with them also! Thank you so much.