[ssphil]

Hi everyone,

This weekend, I drove the 335i for the first time this year and everything was great, and now that I installed my VRSF inlets and 3" downpipes, I am getting random misfires when cruising on the road (70mph).

Now, I am getting an o2 code for the upstream bank 2 probe so I am guessing I must have damaged it while installing the downpipes and it must be the reason why the wastegates won't close but I am scratching my head on the random misfires. When driving in town, there are no misfires at all. I also noticed that when I switch back and forth between 3rd and 4th gear, the engine does not misfire.

Any help would be appreciated!

(I will be replacing the o2 sensor this weekend while I remove the transmission for my clutch replacement)

Edit: Forgot to mention that when I clear the codes with the JB4 menu, the misfire disappears but it comes back a few moments after.

[Mike@N54Tuning.com]

When is the last time your plugs have been changed?

Double check the o2 sensors aren't swapped around or damaged and that the VBAND bolt is not hindering the waste gate. Common errors when installing downpipes.

Mike

[ssphil]

Plugs have been changed 2 days ago at the same time I did all the rest (NGK one step colder, gapped at 0.22) and the V-band bolts are not in the way of anything I suppose since I can manually move the wastegate rods with no restriction.

I read that when an upstream o2 sensor fails, the dme goes into safe mode since it cannot read afr anymore, and that makes sense. I did some logs too and the reading for the bank 2 afr stays at 20 all the time.