Misfires and O2 sensor fault code

I've been having 2729 (Lambda probe thrust diagnosis in front of Kat Bank 2) fault codes for a while now. I've replaced the upstream for bank 2, twice, using Bosch OE O2 sensors. I've reset adaptations as well. Now after 250+ miles of driving a few days after i changed my o2 sensor, i got these fault codes:

during cold start, the engine experienced rpm fluctuations and then turned to emissions increased then limp mode.

2B39: Misfiring with shutdown Cyl. 5
2B3A: Misfiring with shutdown Cyl. 6
2B3B: Misfiring with shutdown Cyl. 7
2B3C: Misfiring with shutdown Cyl. 8th
2B41: Misfiring with shutdown several cylinders
2B57: Engine emergency program activated
2796: Engine emergency program activated
2B46: Combustion misfiring exhaust gas degassing Cyl. 5
2B47: Combustion misfiring exhaust gas degassing Cyl. 6
2B48: Combustion misfiring exhaust gas degassing Cyl. 7
2B49: Combustion misfiring exhaust gas degassing Cyl. 8th
2B4E: Combustion misfiring exhaust gas several cylinders
2751: Lambda probe fault pump current line in front of Kat Bank 2
2729: Lambda probe thrust diagnosis in front of Kat Bank 2

Likely bank 2 exhaust ring gasket. Change both banks.

Redd wrote

Likely bank 2 exhaust ring gasket. Change both banks.

ill try it out thank you! ill keep yall updated

All the misfire cases are in bank 2 on forum. I wonder what is special about bank 2? My car also had misfire on bank 2. Secondary control valve seems to fix it.

aggieshan wrote

All the misfire cases are in bank 2 on forum. I wonder what is special about bank 2? My car also had misfire on bank 2. Secondary control valve seems to fix it.

was yours clogged or something? bc the gasket didnt seem to fix it but i did replace both tho!

Not sure but that was the only thing i can think about to replace.

My car has about 53K, so the secondary control valve wasn’t too dirty.

Is your plenum properly seated? In my experience a misfire is a vacuum leak or unmetered air in the system commonly. An exhaust donut gasket would cause this due to un metered air effecting forward and backend O2 readings per bank. Also unseated throttle body gaskets would do this on the intake side. Are spark plugs torqued properly on bank 2? Are all ignition couls properly seated and plugged in properly?

Scrippy wrote

Is your plenum properly seated? In my experience a misfire is a vacuum leak or unmetered air in the system commonly. An exhaust donut gasket would cause this due to un metered air effecting forward and backend O2 readings per bank. Also unseated throttle body gaskets would do this on the intake side. Are spark plugs torqued properly on bank 2? Are all ignition couls properly seated and plugged in properly?

im sure spark plugs are torqued properly and ignition coils are properly seated but ill take alook again. i do have something regarding the plenum.

there's like a whistling sound whenever i accelerate but only at a certain low rpm's. it's this https://www.m3post.com/forums/showthread.php?t=1698102.

im not sure if that can be a symptom too