your exhaust would likely be ok witha cam, so new klifters and a cam install. then you'd also likely need some extra tuning on your pcm. the zzp one is only so good as a 1.0 that im sure you have. but LI there seem to be a load of guys who tune.

i bad o2 can for sure cause kr. it was killing me for a while, wot it should hit 930 give or take, mine was at .087 wot, and i had knock all over. new o2 kr went away. see i was kr free, then i just started. so i had to figure that one out via a scan.