Knocking noise

[mississippiray]

i have a 2018 duramax 150,000 miles i have owned truck for 3 years purchased used and it coded the first day i had it def deleted and after delete started hearing a knocking noise
when traveling down interstate and reduce speed by just getting off the accelerator and coasting the engine will knock and if i apply brake hard it will stop or start to accelerate again it will stop
hunting solutionplease

 

[TheBac]

Moved to L5P section.

What were the codes? Does the knock sound like its coming from on top of the engine or does it sound as if its under the truck?

 

[mississippiray]

Moved to L5P section.

What were the codes? Does the knock sound like its coming from on top of the engine or does it sound as if its under the truck?

codes were for nox sensors
sound from under hood sounds like

 

[mississippiray]

nox sensor codes
sound comes from under hood

 

[kidturbo]

My thoughts are tune table related. Possibly a change to fuel pressure, pilot injection, or timing that you are now hearing under certain conditions. If that is the change that brought on the noise, I would bring that up with the tuner. Doesn't sound like hardware issue to me.

 

[2004LB7]

Sme of the L5Ps also suffer from the same or similar injector connector issues like the LLY did. Some symptoms are knocking. Might be worth looking into ot

 

[Chevy1925]

Sme of the L5Ps also suffer from the same or similar injector connector issues like the LLY did. Some symptoms are knocking. Might be worth looking into ot

Truck will code if that’s the case… unless the codes were shut off

Knocking in decel sounds like a tune issue. Trucks probably trying to run its injector timing test and can’t due to only partially being tuned out or tables not corrected.

 

[mississippiray]

Motor Ops
Easy Link
Light Tow
4"exhaust all the way
Could this be an exhaust leak there is a couple of sections that show a little bit of carbon buildup at the section joints

 

[Chevy1925]

Need a video of the noise

 

[JoshH]

Try doing an injector small quantity reset with a good scan tool.

 

[mississippiray]

I have tried to attach a video but i can not get the video from phone to laptop without it saying it does not have encoding setup so it want play on my computer or download to the conversation
if anyone has a suggestion for this also im open

thanks for help

 

[2004LB7]

I have tried to attach a video but i can not get the video from phone to laptop without it saying it does not have encoding setup so it want play on my computer or download to the conversation
if anyone has a suggestion for this also im open

thanks for help

From your phone, upload it to YouTube then post the link here

 

[Ron Nielson]

Download the video to YouTube then post the YouTube link here so we can see the video

 

[mississippiray]

I will try in a day or so just got back to email about truck from the holidays
Sorry for being slow