Codes are P2196 (B1S1) and P2198(B2S1) are rich. I just replaced my 3.0l with a remanufatured, new fuel filter, fuel injectors, MAS, all 02 sensors, and PCV valve. When it’s at idle it’s ok and it revs good but when I let it drop to idle it’ll go low rpm and sputter then pick back up to idle, it has cut off a few times from idle as well, tried unplugging MAS and it ran smoother but it took about 10 seconds to drop to idle, tried changing to original MAS still sputtering when I let off, when I did my first start I believe smoke was coming from passenger side header but not driver side, may have a leak could that cause it? Any thoughts? I believe my catalytic converter is also shot, that what I think that sound is. Also I have a oil pressure gauge attached that’s why my check gauge light is on and I no oil pressure

 

You need to recheck the codes and get us the correct numbers

Pretty sure you don't have 12 cylinder engine
P0296 is described as a cylinder number 12 contribution/balance. In essence, this code is stating that the number twelve cylinder in the firing order is experiencing a fuel-related problem.

Rangers don't have an oil temp monitor
P0298 indicates that the powertrain control module (PCM) has detected an engine oil temperature that is higher than acceptable.

 

Apologies, it is P2196 and P2198, don’t know what I was thinking, I can’t change the title but I have corrected the post.