My 2003 mazda v6 came up with code p2197 lean bank
ECU 101;the ECU dont know what is wrong EVER! not really!it only know (For examp) that an input is bad. that is it.the bank 2 front is stuck , you and take that to the bank.but why,?1: it's bad. (replace it)it will go bad at 100k miles , and is in the service schedule and is a fact. they dont last the life of any engine. Unless blessed.2: that bank is stuck rich or lean. (a scan tool shows which)(caused by big list, leaking/clogged/dead injector ; vacuum leaks, etc)RTMok , open FSM. (or google has 10mi +l hits on topic, )page 1, bank 1 is left bank 2 is right.sensor 1 is front, sensor 1 is AFR adjusting sensor.sensor 2 is only a CAT monitor.left means drivers perspective seated, in car.this is SAE.org rules. it's a USA standard.i can make up good $20 sensors using Delphi parts. at some dealers its $200 plus 1hr labor,or if you want a PNP $ensor, then buy oen on amazon.Bosch invented it and does sell a universal sensor that worksthey have an ecatalog , its all there.if the new sensor fails then the EFI is bad.the scan tool can show you the facts.now 1 more pro ASE fact (test0we have a trick (2nd week of class under EFI)we can force any engine lean or rich.its not magic.we do that and try to get the seemingly bad B2S1 sensorto the other rail. say 0v , i force it to 1v or at 1v i force it to near 0vthis tells me the O2 sensor is not dead and that the bank has issues.All ASE mechs know this test and saves huge money and wasted parts and labor so you cans see that smart labor does save total costs.also we can just do the diagnosis.we tell you the 02 is dead.you go home and buy a new one.its your choice, what to do. but is it more complex than you know.its a closed loop, understand that, and all this makes senses.google that.