Vehicle is 2005 Z71 Tahoe with the 5.3L. Long story short I got the infamous rear bank knock sensor code (it was completely corroded as expected).

I pulled the intake manifold and changed both knock sensors after putting everything back together below are the issues, trying to figure out what I did.


Idols extremely rough
Interior lights flicker at idle with rough idle
No Power at all
Getting on it or over about 20mph check engine light starts to blink...slow down and it stops blinking.

Thanks
So much

 

I want to assume you did new intake gaskets aswell??

If it was me, I would remove the intake again and make sure you didnt miss anything. Check over the gasket and surface on the heads to make sure it's getting full contact. Put it back together and see whats up.

To me it sounds like a bad vacuum leak or something is unplugged, maybe even an injector.

 

Yes new gasket, and it looks like it's making good contact. If there was a vacuum leak wouldn't I hear it?

What would happen if I got a couple of my injector plugs flipped around? I definitely didn't miss any plugs, idk I'm just at a loss. I hate to take it in and have somebody clean up my mess when I think it's gotta be something easy

 

Check the connectors for the injectors

 

Whats weird is the RPM gauge is rock solid. But you can FEEL how rough its running. The truck shakes pretty noticeable, and when you get on it a little bit the truck shakes even worse

Flickering interior lights is what is really throwing me off, how could that be tied to a coil pack, injector problem? They only flicker at that rough idle, when you get the rpms up, they go away.

Thanks

 

Physically check your injector plugs. I thought the same thing when I did mine and it turns out 2 of them didn't fully seat. While your at it, check any other plugs or grounds you may have removed while servicing the Knock sensors.

A flashing check engine light is an indication of a severe misfire.

If you can check the codes it might also point to something specific.

 

I don't see how its possible with how the harnesses are laid out, but hypothetically speaking If I had the injector plugs switched around, would that cause a misfire? Im going to go back through everything today

 

Sounds like a vacuum leak somewhere.

Did you replace the knock sensor harness? If not, you should. The corrosion attacks the harness as well most times.

 

Replaced the whole harness... Ended up finding that I had an injector plug that didn't go in smoothly and bent a pin over. So I was getting an incomplete injector circuit and misfire code.

Thanks for y'all's help, running smoothe as a kitten now

 

Glad it's fixed.