SOLVED - Check Engine Codes After a Valve Cover Gasket Replacement - P0115, P0110, P0325, P0330

I just replaced my valve cover gaskets, spark plugs, spark plug seals, cam shaft seals, PCV Valve/grommet and throttle body gasket.

The engine starts up right away. Right after I finished putting everything back together, the truck idled high for a bit (1200 RPMs) but I took it for a test drive and it drove perfectly fine. It now idles around 750pm even with the AC running and I didn't notice a single difference between how it drove before this job and after.

Nevertheless, as soon I started it up, the check engine light was on. AutoZone told me the four codes are:
P0115 - Engine Coolant Temperature Circuit
P0110 - Intake Air Temperature Sensor 1 Circuit
P0325 - Knock Sensor 1 Circuit (Bank 1)
P0330 - Knock Sensor 2 Circuit (Bank 2)

After I ran the diagnostic, I found that one of the grounds (on the upper plenum on the drivers side) was loose so I tightened it, disconnected the battery and then started it up again. The CEL went off but after a very short (15 second) test drive it came back on again.

Any idea what this could be?

 

The high idle initially I would guess you had the battery disconnected?

Try clearing the codes now that you've dealt with the ground wire being loose and see what happens.

 

I did that already and the CEL came back on.

I think the high idle may have to do with cleaning out the throttle body. I read that after cleaning, the computer needs to reset. (https://www.youtube.com/watch?v=Ks0IRj_kRYs)

 

That is true, I've heard that. Drive it for 50 miles or so and see how she goes

 

A ghost fart that burns when you pee... Huh.. now there's an oddity you don't hear about everyday. Lol.

Anywho, moving on to helpful information... Is it possible you pinched the wiring harness somewhere, when putting the intake manifold back on? It's a possibility that you have to consider, especially after doing all that work, it is easy to slip up sometimes.

 

I can see how that would cause the knock sensor codes but would that trigger the other two codes?

 

The other thing I could say is check fuses. Make sure they aren't popped.

 

recheck the codes first before you assume anything.

 

After I replaced the loose ground, two codes cleared and two remained. The two remaining codes were for the two knock sensors (P0325 and P0330). Thanks to another post regarding a similar issue, I knew to recheck for loose wires and found one last wire behind the timing cover that was disconnected. Disconnected the battery and reset the code and now the CEL is off. Thanks for the help!