P219A or P219B

Lately my engine light is on and I scan it with my tool show me this code P219A sometimes P219B. My OBD scanner can't point exactly what is causing but more to prefer manual service something.
Any of you guys counter with this code?
Trying to check any leaking vacuum but can't find. Thanks for the guideness and help.

 

Any exhaust modifications, exhaust leaks, etc?
Those codes essentially mean the PCM is seeing the air/fuel ratio sensed by the AFR sensors is changing quickly between cylinder firings, P219A is for bank 1 and P219B is for bank 2.

There's a long list of things that can cause those codes but exhaust leaks upstream or near the AFR sensors would be the first thing I'd look for.
If that's good then you need to see if the AFR sensors are working properly, if those are verified to be good then the fun begins.

 

I did just put straight pipe at Y pipe after catalyst,
Probably leak between sensor bank 1 and sensor bank 2 in that case... I will double check again to make sure no leak especially on headers.
Thanks Dm93

 

Sorry just get back again bc back then the code was clear and now coming back and I had been try figure out the leak vacuum or exhaust I can't find anything, everything seal no leak,