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Discussion Starter · #1 ·
I am considering purchasing a 2011 3500 and the cat has been removed.
My question is, if the cat was removed would it of had to of been deleted and would the def have to of been deleted as well or can only the cat be deleted.
I currently have an ‘09 so I’ve never delt with the def.
Thanks
 

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2016 Chevrolet Silverado Duramax
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NO DELETE TALK ON THE FORUM.
 

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I am considering purchasing a 2011 3500 and the cat has been removed.
My question is, if the cat was removed would it of had to of been deleted and would the def have to of been deleted as well or can only the cat be deleted.
I currently have an ‘09 so I’ve never delt with the def.
Thanks
My guess is someone put on an aftermarket exhaust. They used to sell "test pipes" that would bolt in place of the DPF but for the CAT I believe you would have to replace the exhaust. My guess is you do not have a DPF on that truck which means the tuner would have deleted the function. Not something that would be EPA or California friendly. You may need to either replace these items or purchase them and put the tuner back to stock. Dean
 

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Discussion Starter · #5 ·
Thank you, that was my thought as well but I was looking for confirmation.
I appreciate it.
 

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Discussion Starter · #6 ·
NO DELETE TALK ON THE FORUM.
I’m not talking about deleting anything, my current truck is bone stock.
I was asking if something had been what to look for.
Some one needs to delete all of the “delete conversations” on the past threads if you can’t ask questions.
 

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2017 GMC Denali 2500HD, 3.5" Rough Country Lift, 305/55R20 Yokohama Geolandar A/T
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I’m not talking about deleting anything, my current truck is bone stock.
I was asking if something had been what to look for.
Some one needs to delete all of the “delete conversations” on the past threads if you can’t ask questions.
The thought is that we would leave those threads there for folks to be able to research the topic, which has been beat to death, without having to make new threads asking questions that have been answered previously in said historical threads.

And no, our volunteer moderation staff will not be spending the man hours to find and remove historical posts that mention deletion or alteration of emissions controls.
 

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Discussion Starter · #8 ·
I’m glad to hear that.
I researched my question but couldn’t find the exact answer I was looking for until I posted the question and someone answered.
 

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"THEEPASUCKS"
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I am considering purchasing a 2011 3500 and the cat has been removed.

My question is, if the cat was removed would it of had to of been deleted and would the def have to of been deleted as well or can only the cat be deleted.
If only the Cat was removed NO, if the DPF and DEF tank was removed YES. It would go into Limp mode and throw a check engine light if not tuned properly beforehand. Someone correct me if wrong.
 
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If the DOC is gone, then it is deleted.

You can not remove the DOC, or any part of the emissions system for that matter, and not be deleted. So if the dpf and scr assembly is still under the truck, but the DOC is not, then someone had the truck deleted and slapped the DPF and SCR (its one welded unit) back under there in order to sell it or trade it in.

The DOC is monitored no differently than the DPF is. There is inlet and outlet temp sensors, and they are monitored during normal operation, as well as a regen.

So if the DOC was removed, and just say the stock tune was still there, it would rather quickly throw catalyst efficiency codes and would soon go into a derate condition.
 

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In my opinion, I wouldn't spend much money on an altered truck that you don't know much about. You need to know who did the tuning, when it was done, what tunes are present, and what supporting alterations have been added as well.

Without knowing at least who did the tunes, you're asking for problems later.
 

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In my opinion, I wouldn't spend much money on an altered truck that you don't know much about. You need to know who did the tuning, when it was done, what tunes are present, and what supporting alterations have been added as well.

Without knowing at least who did the tunes, you're asking for problems later.
Completely agree. There would be nothing worse that a cranked up tune going when pulling a heavy load. Cracked pistons and blown head gaskets can't be far off at that point. D
 

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I am considering purchasing a 2011 3500 and the cat has been removed.
My question is, if the cat was removed would it of had to of been deleted and would the def have to of been deleted as well or can only the cat be deleted.
I currently have an ‘09 so I’ve never delt with the def.
Thanks
If you haven’t bought it yet, I suggest to move on and continue looking.
Going from a 09 to a 2011, I wouldn’t, you might be in for more problems known for the LML early years.
On a LMM the DOC does not have sensors, I don’t know about the LML.
Is the DOC the only thing missing ?
 
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I am considering purchasing a 2011 3500 and the cat has been removed.
My question is, if the cat was removed would it of had to of been deleted and would the def have to of been deleted as well or can only the cat be deleted.
I currently have an ‘09 so I’ve never delt with the def.
Thanks
Not sure what you mean by CAT? There are two completely different systems on the truck, a diesel particulate filter that uses diesel to regen it, and a selective catalytic reduction system for NOX that uses DEF as a catalyst. Normally the SCR is after the DPF so it does not get poisoned by the soot. These systems are complicated and there are lots of software to prevent them from being bypassed. It is very easy to real screw up the vehicle with an aftermarket delete system not to mention it is of course illegal and will void any remaining engine warranty. Also if you live in a state with emissions tests it will of course fail. Personally I stay a 1000 miles away from any delete system, nothing but drama and trouble for nothing.
 

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DOC aka CAT same part
 
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Yes it was. All the LML trucks have it, as do the LMM trucks for that matter.
 
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It looks like GM for a while had DOC, DPF and SCR.
 

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+1 the above post about skipping a truck where you have no idea of the history. My truck was fully deleted by the previous owner. Haven't been able to get any information from them about what tune is on it. I'll be adding the DOC back to cut down on idle smell, but even that is an expensive part and a pain to reinstall.
 

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The history of fully deleted tells it all, along with asking for suggestions also tells all.
Do what you want it was just a common sense suggestion, to pass it up.

You might check on getting a home equity loan to pay out of pocket for replacement emissions stuff.
As far as knowing what I’m talking about, been there done all of this.

FYI, if the exhaust was replaced from the downpipe back, it’d be eaiser to get a complete factory DOC pipe from the downpipe with 4 bolt flange at the end, then add a 4bolt flange to your existing exhaust.

Putting a factory DOC back on will help with exhaust smell, a aftermarket CAT will NOT help at all, only help with making your wallet lighter.
This I’ve experienced myself.
Tried straight, then stink overwhelmed me, added a Magnaflow CAT this did absolutely nothing, after 5 yrs of excessive stink I put the stock DOC back on.
 
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