New knock sensors and now no start...

[aces-n-eights]

2006 Tahoe, 5.3. I got a CEL a few months back that the knock sensors were a pending code. Replaced them today and now the truck won't start.

I'm getting the following codes.

P0068 Powertrain
P0107 Manifold Pressure/Barometric Pressure circuit low input
P0332 Knock Sensor 2 Circuit Low Input, Bank 2

The truck only cranks and no start. The DIC says "Reduced Engine Power".

So I'm wondering if I forgot to plug something back in, but I've triple checked and there are no loose wires or connectors.

Any suggestions?
Thanks guys!

 

[aces-n-eights]

OK, figured it out, cleared the codes and it started right up. Sorry to bother y'all!

 

[Tonyrodz]

OK, figured it out, cleared the codes and it started right up. Sorry to bother y'all!

What was the issue?

 

[Scottydoggs]

only thing i can think of is he powered the key while it was all apart. pcm saw all them things missing and set codes.

id crap my pants a bit too if that happened to me.....

 

[aces-n-eights]

only thing i can think of is he powered the key while it was all apart. pcm saw all them things missing and set codes.

id crap my pants a bit too if that happened to me.....

That's exactly what happened. And yes, I'm a dumbass. I'd surely starve if I had to make a living as a mechanic!

 

[Tonyrodz]

That's exactly what happened. And yes, I'm a dumbass. I'd surely starve if I had to make a living as a mechanic!

Happens to the best of us. At least you resluzed what happened.

 

[Scottydoggs]

That's exactly what happened. And yes, I'm a dumbass. I'd surely starve if I had to make a living as a mechanic!

hey at least you have a scanner to read and then clear codes. so many dont have even the cheapest of scanners.

i got a 15 dollar actron years ago. it lives in my console. never know when your gonna need it.

 

[aces-n-eights]

Thanks. And yes, my OBD scanner is in my center console.

Just for grins I thought I'd show a pic of the old sensors next to the new ones.

 

[Doubeleive]

hey at least you have a scanner to read and then clear codes. so many dont have even the cheapest of scanners.

i got a 15 dollar actron years ago. it lives in my console. never know when your gonna need it.

true I was having intermittent transmissions problems once, stupid trans would error out and sit dead in the water (no go), clear the code and you could go again until it would error out again, my little actron stays in the truck at all times now

 

[Scottydoggs]

Thanks. And yes, my OBD scanner is in my center console.

Just for grins I thought I'd show a pic of the old sensors next to the new ones.

both under water. great design.

 

[HiHoeSilver]

hey at least you have a scanner to read and then clear codes. so many dont have even the cheapest of scanners.

i got a 15 dollar actron years ago. it lives in my console. never know when your gonna need it.

Thanks. And yes, my OBD scanner is in my center console.

Just for grins I thought I'd show a pic of the old sensors next to the new ones.

true I was having intermittent transmissions problems once, stupid trans would error out and sit dead in the water (no go), clear the code and you could go again until it would error out again, my little actron stays in the truck at all times now

X4. Autel is always in the truck.

 

[aces-n-eights]

I thought I'd give a little review of my experience replacing knock sensors in the event someone does a search in the future.

As I stated earlier, I am no mechanic. Fairly handy but not a lot of experience. I watched several YouTube videos and figured I could do this. Especially after getting an estimate from a local shop for almost $900 to do the repair. My cost was about $180 for 2 knock sensors, harness and manifold gasket.

I used a 8mm, 10mm and 22mm socket, a screwdriver and a pair of pliers. I needed to buy a couple of tools that I did not have - a 3/8 fuel disconnect tool ($4.50) and a pick with a hook shape ($8.00) to remove the fuel injector wire harness connector.

It took me a little over 5 hours to do the job. It is basically removing the stuff in the way of the intake manifold and removing the intake. The sensors are in the valley below the intake manifold. Took my time, cleaned everything and other than my brain fart of turning the key, it all worked fine.

One trick... in one of the videos I watched, the guy recommended running a bead of RTV just outside of the rubber seal which seats above the knock sensor. This is to shunt water away from the hole the sensors fit in. Good idea.

Go for it - not too hard!

 

[Scottydoggs]

i sealed the caps too. 05 6.0