Resolution: shop said they billed me 1 hr for KS, 3 hrs for oil trap (which I only had them install since they had the IM off). So I got a check for $90. The mechanic says he "remembers" tightening the bolt - so be it. What else would he say, especially in front of his boss. I like the guys in the shop, but the bossman is a peckerhead, to say the least. He must not care about losing business - that's his choice.

On the positive side, I learned a lot about the shop and my car, even though I have a full time job and family and I'd rather not have to mess with any of it. The car does seem to accelerate a lot better with no 1-4-3 DTC for missing knock sensors!

Any way you slice, there is a price to pay, which is why I ride my bike to work.