I own a 2001 WS6 A4. Sometimes when I floor it the car feels like it doesn't have any power (almost like its bogging down). When it shifts gears, only at wide open throttle, it makes a weird popping noice, almost like a backfire but not as loud and does a little lunge. Its really hard to explain. It threw a few of codes recently. The front left 02 sensor, an emissions code, and the last was a secondary induction code. What could these be? Any ideas as to what is going on and what I need to fix. Autozone reset the light and it hasn't come back on since. I know its not a very good explanation but I really cant explain the noise. The car is all stock exept for cat-back exhaust and free mods. Thanks in advance for your help.

 

Me and you could have the same problem. What mods do you have or any at all?

Check out this post and see if that seems familiar to the problem i'm having.

http://www.ls2.com/forums/showthread...threadid=92620

 

Not quite the problem Im having. Mine will do it at any speed and I cant pump the gas to make it quit. I used to have mods but I returned the car to stock to see what the hell is wrong. Ive heard it could be the Mass Air to the cats. I just need some suggestions as to what it might be before I take it to a dealer for them to charge way too much to fix a problem that I know I can repair myself. I just need to find the problem first.

 

possably o2 sencer bad