[franksinatra]

After installing headers, I am experiencing a rough idle. I haven't got my tune from StageFP yet (I've already emailed, just waiting for Bob to send the tune file). I've been looking at my O2 sensor voltages and I'm not sure if one of them is possibly going out.

Bank 1 Pre Cat: between about 1.9 and 2.1V
Bank 1 Post Cat: between .7 and .1

Bank 2 Pre Cat: between 1.5V and 2.2V
Bank 2 Post Cat: between .7 and .1

If I unplug bank 2 pre cat, the rough idle goes away. Do those values look good to everyone? If not, is it a bad sensor or could it be something else?

[hassmaschine]

the pre-cat sensors control fueling and are widebands. the post-cats are for emissions and are narrowbands.

I'm not sure the voltage will tell you without a reference value, but what are the fuel trims like? Also, a good tune will adjust the parameters for the O2 feedback because the sensor position has been moved further downstream (the N52 sensors are fast enough for this to make a difference). Bob is aware of this so I'd suspect your car will run better once you get the tune.

[desertman123]

Luckily the price for the OEM Bosch O2 sensors dropped a bit. They were like $150 a while ago but now closer to $70-120

Bosch 17098 and 17099 if I remember right

[modelm]

I had the same issue, and I think it's normal. I also had my headers installed before the tune. After installing my headers, the idle was very rough. After driving for several hundred miles it normalized.

Subsequently, I got the tune installed and the rough idle returned. After I cleared the adaptations, it normalized.