It has been running like crap for a while, that is why I changed my plugs each time just to see if that was the problem and it always turned out not to be the problem. This was the first code it has thrown, but I have lost about 2 miles per gallon here the last few months.has it just started this and ran fine on the plugs you changed 3 times?
could be a damaged cam position sensor, crank postion sensor or bad coil(s)
I'd suspect something didnt go quite right with the cam swap...
Think the O2's could cause a problem like this ? The reason I say it runs bad is it has a bad miss or stumble between 1500 - 3500 rpms but still seems to pull hard at WOT. And the smell of the exhaust has changed to a real real rich smell.check your o2's too.. do a datalog