Diesel Place banner

LML-OK To Drill Out Airbox?

7.3K views 13 replies 9 participants last post by  97chevor  
#1 ·
I haven't been here for a few yrs. and hacen't kept up on mods. While replacing the air filter on my 2016 Chevy, I wondered if drilling holes the bottom of the box would help with airflow. So I did, and now I have an engine light. Did I screw up? Do I need to tape up the bottom of the box?
 
#6 ·
Well I went out and rechecked the filter install and it was ok. Pretty easy to replace, so I didn't expect anything wrong. I reset the ecm and the engine light disappeared.:confuzeld I suppose I didn't reset correctly after replacing the oil and its filter a couple days ago.
 
#8 ·
I'm not sure what you mean by "Resetting the ECM" after an oil change.

The ECM doesn't need to be reset after an oil change. The interval needs to be reset, but that's it.

I suspect the light will return, when it does, go to your local autoparts store and get the code number.
 
#9 ·
I installed a S&B air intake/filter on my 2011 LML. The bottom had a door that could be left out if more air was desired. I left it out, It was the size of the bottom of the air box. It also had a large opening in the side toward the fender. No codes afterward. I don't believe drilling any amount of small holes in the bottom of the OEM box could begin to equal what an S&B would be. Possibly loosened the max air flow sensor?
 
#10 ·
I'm laughing. I spent good chunk of my life in plant engineering at GM. I even did projects at the Flint plant that builds the Duramax trucks. The company spends ungodly amounts of time and money, endless dynamometer runs, running the preproduction truck up Pikes Peak, and on and on, developing engines so that each part is correctly sized for the power developed - then some shade tree mechanic starts drilling holes in it because HE knows better.
 
#13 · (Edited)
Haha! I missed your post before I wrote mine! Great minds!:agreed: The first thing the LMM know-it-alls do is cut out the vanes in front of the filter, not understanding that those are there to fling the dirt to the outside using centrifugal force, thus making the filter element last longer. It does NOT obstruct air flow.

On the other hand, I am guilty of having (in my youth) flipped the lids on GM air cleaners on 60s and 70s cars. A move that was recently justified on Engine Masters TV show,
 
#11 ·
I get a kick out of the shade tree "engineers" that want to get out the tools and start modifying the stock air filter box, without any dyno tests to justify their mods. Same with the LMM guys who hack up their boxes. It doesn't help, and might actually hurt.

Look at the link G2GBY posted above, especially post #10.
 
#12 ·
Wow. Just start drilling holes. SMH.
 
#14 ·
Well, as far as I know GMs, fix for long term driving in blowing snow on the LMM and older, was to drill holes in the air box cover to prevent snow from filling the air box. "The heat from the engine melts it that way." I have experienced truck can still can through code do to soaked air filter. Always carry a second air filter.