2001 Yukon P0305 and P0332 and P0446

I'm new here I really appreciate any help you can provide.

I have a 2001 Yukon 4.8 2wheel drive that we bought new. It has 142,000 miles on it. Have never had serious problems. Did new spark plugs at 100,000 did not change the wires. Have had to remove the air intake assembly and do some cleaning with carb cleaner and a rag a couple of times when it would die at idle. That has always fixed it right up.

Code P0305 shows up occasionally for about the last year. I never knew what the problem was, a it usually went away. Engine runs pretty smooth. I does make a knock that sounds like spark knock when accelerating. Could that be because of the code P0332? What is involved in changing that sensor? Can it be tested?

Any ideas about the code P0446? that is the only one that is a pending code. The rest are trouble codes.

Thanks

Code P0332 is your Knock sensor if that is not sensing correctly then you will notice a piston knock. you will have to diagnose if you have a wiring problem or the sensor it self. normally a wiring connection problem these sensors rarely go bad
The P0446 is an evaporative emission vent system performance
This code could be anything to do with the venting system fuel tank pressure sensor,fuel pipes and hoses,vapor lines,fuel cap,evap emission canister purge solenoid.
Indy,
PS, if you think you can tackle this and have the tools, just ask if you have any more problems. for the P0446 best done at the GM dealer you could save money that way, as on this job without experience you could end up throwing parts at it till repaired, which can get very expensive in emission problems .