Knock sensors...
 

About a year ago I started getting the dreaded knock sensor code. I replaced the sensors and the harness and things have been fine until recently. Last week I had the dynotune done and the next day two codes started coming up. Knock sensor bank 1 and bank 2 low input. I messed with the connection on the harness and cleared the code. They just keep coming back now about every 20miles. What should I do? Why would they have already went out again?

Were they delco sensors and did you use rtv to stop moisture from going back inside?

Yes. And no I didn't use rtv

Check that harness really good and make sure it isn't pinched or damaged. If either the sensors or harness is messed up, could explain some of your lack of power.

I'll check it all out tomorrow. I'm also getting a p0453..

If you didn't use RTV on the rubber plugs, chances are pretty good the sensors are corroded from moisture entry. If you didn't replace the knock sensor seals in the valley wells, you likely have a lot of condensation in there. Low signal = low voltage response = bad connection.

I replaced the seals. I just figured they were good enough to keep water out

No. Seals alone are not good enough. Should seal over with RTV and build a 1/4" dike wall around both of them to keep water out.

Could you use dielectric grease instead? Or does it need a "hard" seal around the connector?

Well two days ago I had to drive through some deep water to get home and I think the truck got water in the intake... I got it home and it would barely idle so I took the filter off and left the hood up in the garage to dry out. Yesterday it ran fine all day, and then I drove two hours to my home town. For the last 35min of the drive I had a flashing service light for engine misfire and I barely made it. I left a fan blowing in the intake all night and am gonna change the oil now. What else should I check or do? I don't want to blow this motor up