I just recently had a buddy make an exhaust manifold for my 98 328i that allows for much better flow, but also has no way to incorporate the fan that blows fresh air into it at cold startup. I've had it in for a couple of weeks, and the check engine light is on (orange). I don't know if this could be an O2 sensor, which would be about due for a 60k replacement, but what I am really concerned about is if I need to keep that fan connected (in which case I would gladly go back to the stock setup), or if there is any way to safely cut it off completely (right now it just blows air into the engine bay). I know this is something I should have checked into before doing the conversion, but I did ask one mechanic beforehand, and he told me "it just blows fresh air through the exhaust to help clear the cats after it's been sitting a while. It's not really necessary..."
I hope I haven't just opened a can of worms. Any helpful advice would be greatly appreciated... :confused
I hope I haven't just opened a can of worms. Any helpful advice would be greatly appreciated... :confused