high idle and engine knocking

I have a 2006 Acura RSX base model I just bought the car a couple months ago and maintenance on the vehicle has barely been done if ever a car has 160000 miles on it so I've been going through and trying to get as much maintenance and things changed and cleaned as possible yesterday when I was working on it I pulled my intake off to work on it I also pulled my mouth and used sensor cleaner I topped off my engine oil in my antifreeze put everything back together double checked took it for a drive and started ticking it gets louder as the RPMs go higher and then when I stopped to look under the hood my RPMs were at 2000 and weren't going down at all I stopped several times to check because it's a new thing the knocking noise coming from the passenger side sounds like it's inside the crankcase of the valves or something I do have CEL codes 4 knock sensor my Upstream O2 sensor they've been there since I got the car and the guy that I got the car from that they've been there for a long time the car's been running great since I've been doing maintenance on it but now all the sudden I do those little things and I'm scared to drive it anybody encounter this or have any suggestions thanks

high idle and engine knocking