My 2006 with Kooks, Mopar Cai and Mopar exhaust has lately been blowin some serious black smoke. At WOT you can hardly see out the back window. It is worse then my diesel ever worse. Plus, it friggin stinks and my fuel mileage has gone from about 12 to 9. Anybody experienced this problem or have any ideas? Could it be an 02 sensor problem? Also, other then that it is running great. No loss of power.

Not only that, but now my key is stuck in the ignition. Looks like the cylinder has shifted and will now not release the key.

WOW a string of bad luck.

I do believe it is the O2. Did you just have the Kooks installed? If not one might have be damaged and have gotten progressively worse.

Actually installed the Kooks 2 months ago. We've just been messing with the 02 sensors trying to see if we can clear the CEL. No such luck. So, it has to be that I would assume. Thanks.

Sounds like they crossed the primary and secondary o2 sensors or your cats are clogged but to early for that to happen.