Well my car is acting funny again, i have a 98 audi a4 2.8 with about 170,000 miles. It starting acting as if it was about to stall, so i let it just sit there and do it's thing. It was fine, but then when i got to the next traffic light i stopped, and the car stalled on me. I tried to start it back up, it acted like it was about to die again but kept running. I took it home, and got my scanner out and found these fault codes. P1127 and P1129. So this means it's too rich i believe. I am about to change the oxygen sensors, but before i buy them i want to make sure with you guys that this is actually the problem. If it is the oxygen sensors why would the car stall? I checked all the vacuum lines, and i don't see any leaks. I am so confused, i hope someone can help me out here.

Thanks in advance to anyone that might be able to assist me here.