If the Sensor was actually bad, yes it would set a code. Depending on the year, I believe 1 of these 3 would apply.

P0325 Knock Sensor Circuit Malfunction
P0327 Knock Sensor 1 Circuit Low Input (Bank 1)
P0332 Knock Sensor 1 Circuit Low Input (Bank 2)

Corrosion could also affect the sensor's reading's.

If the tune is back to bone stock and you can Physically hear the knock, then something is wrong. It could be the gas, could be carbon build up, could be other things. As previously mentioned, Try some fuel injection cleaner and higher octane and see if still shows up.

Keep us posted on what you find.

 

You read my mind

I just seafoamed and all kinds of nice smelly smoke came out. But still have a problem. I just put a can of seafoam in the tank along with a bottle of lucas. I topped off the tank with 93. Drove around and still have it.

I think I have ruled out something rattling in the exhaust or under the hood as most of the time I hear the noise the maximum spark knock retard goes up. Never goes over 4 and averages 2. Sounds like a muffled marble rattling sound.

I am getting 1, 2 and 4 misfires across all cylinders intermittently at different times. Was really getting it when I was reving it in park. When I get 4 I can feel it in park. I don't feel the misfires in drive. Driving I could only get it to do 2.

LTFT's are averaging around -7.8
front bank O2's are giving a nice wave from .1-.7
rear O2's are slower of course but go beteen .2-.6

I am not going to drive it tomorrow, then I will pull the plugs and replace them next. Will ohm the wires too.

It is pretty frustrating. It still pulls really hard. Never had a problem before and it doesn't do it all the time like a mechanical failure.

 

if i run cheap gas my does it horrible even on stock tune run 93 all the time havent had a problem since

 

If you can Physically hear and feel it while revving the engine with no load on the vehicle, I would be concerned that something Else is wrong internally.

 

I can't feel the knock and it does not knock in park revving. Scanner shows no knock in park. Just a few misfires.

It does not knock all the time.

What I felt was the 4 count misfire in park.

I hear the knock while driving down the road.

 

Ok that makes more since.

Aside form wires an plugs for normal maintenance, You might want to try the Sea foam through the intake and see if you can knock the carbon off. Check it out on you tube. or the companies website.
Poor into brake booster hose while running and turn the vehicle off and let it sit. Do not kill it with the Sea foam and do NOT poor it in after the engine has stopped.

The Idea is to get just enough fluid to sit on the pistons to break the carbon down. To much fluid can hydrolock the motor. There is actually a few guys that have done it on you tube and found out the hard way.

 

I think I am narrowing it down to either carbon buildup or a misleading IAT

Yesterday I noticed that while I let the truck idle the intake temp reached 138F
the temp outside was 72F

I drove it to see if the temp came down and the outside was showing 68F and the IAT reading wouldn't go lower than 88F. Any time I stopped it went up quick. I know it gets hot under the hood but seemed abit high to me.

Note that today it hasn't knocked. I have tried everyhting to get it to do it. It is only 62F out right now. So either the Seafoam in the intake and tank helped or the IAT is reading wrong. Iwill report back once I have some time on it.

 

That seems possible.. ive seen IATs never get close to ambient with a intake on there.

Check it first thing in the morning when its been sitting up all night and cooled off. it should be within a couple * of ambient.

 

Will do.

I am really leaning toward carbon buildup. It knocked a little today but 90% of it is gone now. I will run this tank through and seafoam the engine again. Searched more and saw alot of guys talking about carbon giving them knock. I haven't ran anything though it before and I have had it since 25K miles. Always was under the impression that since it is flex fuel you were not supposed to put additives and cleaners in.

 

Had to be carbon buildup. 95% of it is gone. Rarely does it now. I am sure another can of seafoam will cure the rest. Thanks for the replies.