kast1376

My friend was behind me last night, and noticed that it smelled like my car was running rich, or no Cats. Well the car has cats, so that eliminated that answer.

Will a swap from a stock H to a catted X cause my car to run rich? I am not throwing any codes, nor is my CEL coming on. I do have a small exhaust leak on the driver's side manifold where it joins the mid-pipe, could this be part of the cause?

I just don't want to spend a pile of money tossing the car up onto a dyno to have it tuned if I do not have to.

lizzyfan

Sounds like the problem

kast1376

Would an exhaust leak cause the front O2 sensors to read a false lean, and increase the A/F ratio? I can only hear the leak when I am moving, at idle it is almost un-hearable. There is no gas smell at idle near the driver's side manifold either.