Car is a 03' Hyundai Accent 1.6L. 104K miles CEL is on. Code is P0172, too rich bank 1. (I'm guessing forward O2 sensor picked that up?) Sometimes when accelerating from a slow speed, low RPM's (car is a stick) it will loose power. Feels like it's running out of gas. Back off a bit & let it gently accelerate than at a bit higher RPM it will accelerate smoothly. My code reader gives a freeze frame. So when it threw this code. 45 MPH 185deg. water temp 2160 rpm 12.4 in Hg 10% load L.T. fuel trim -23.4% S.T. fuel trim -25% Looks like it's trying to lean things out. Do I read that correctly? Fuel filter changed last year. This car does not have a mass air flow sensor so nothing to clean. MAP sensor was replaced few years ago under warranty. Looking online it's pointing to possibly O2 sensor. I hate to throw parts at a problem. With the software I can (will try it tonight) look at the real time O2 sensor output. So is it possible to tell a bad O2 sensor with the car just idling, or running on the highway? It's running normal in all other cases.