Hello all !

Just got p2195 code rear A/F sensor signal sensor 1 bank 1 signal stuck lean..

2004 acura TL 150,000 miles. It still runs and drives find just wondering if I should go ahead and buy a new o2 sensor. Bank 1 should be behind cylinder 1 correct? Or on the cat?

 

Bank 1 is the cylinder 1 side, bank 2 is the cylinder 2 side. That said, bank 1 is on the rear of the engine, next to the firewall. There are two sensors on the cat. Sensor 1 is on the top and sensor 2 is on the bottom.

So bank 1 sensor 1 is the sensor on the rear of the engine on top of the catalytic converter.

If it was me, I would measure the sensor output to make sure it's the problem before just replacing it as the problem could also be in the wiring.