Emissions delete... pros? cons?

AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
Ok, so as some of you know, I ended up with a deleted and tuned (from who knows where) LMM for my first diesel. I'm curious as to what the advantages/disadvantages are to leaving it deleted vs making it legal again? I'm noticing an exhaust smell in the cab and I'm not sure if that's as a result of the emissions delete or the stupid axle dump.
 

2004LB7

Well-known member
Dec 15, 2010
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Norcal
the smell is from the lack of a catalytic converter. it is likely made worse from the axle dump.

pros: less maintenance or things to go wrong, possible MPG increase. noise if that's your thing, less weight and more room underneath.

cons: Smog test failure if you have that in your state, noise if that's not your thing (mufflers & resonators can help with this), possible fines for getting caught, need for a tune, possibly a retune in getting dealer work done, Denied warranty is common.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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Mid Michigan
Not really something we talk about openly anymore due to EPA interference.



But if you have an axle dump exhaust, thats probably part of the problem. Also check the connection between the down pipe and the front pipe of the exhaust. If the connection isnt spot-on and tight it can put smells in the cab.


Also, moved this over to the General Exhaust section.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
the smell is from the lack of a catalytic converter. it is likely made worse from the axle dump.

pros: less maintenance or things to go wrong, possible MPG increase. noise if that's your thing, less weight and more room underneath.

cons: Smog test failure if you have that in your state, noise if that's not your thing (mufflers & resonators can help with this), possible fines for getting caught, need for a tune, possibly a retune in getting dealer work done, Denied warranty is common.



Pretty much covers it.

Could make for a harder re-sell here in phx for a deleted truck (won’t pass emission inspection) but outside the county isn’t an issue as it’s not required.

On an 08, I feel it’s benefitial for the engine to have the delete as the potential to wash a cylinder down from a worn injector is far less. 07.5-10 uses an extra injection cycle on the exhaust stroke to send fuel to the dpf for regen unlike the 11-up trucks.



As for talking about it here, I think guys get a bit confused on where to “draw the line”.

In this case, we are not suggesting a shop to delete the truck and tune it. We are not pushing for a movement of deleting trucks. And the op isn’t here asking vague questions looking to score info on someone/some place for reasons we don’t know.

I don’t see why we can’t help a personal owner see both sides of the situation and let them make their own educated choice on what to do.
 

zakkb787

<that’s not me...
Sep 29, 2014
2,340
52
48
Granite Falls NC
I would definitely leave the tunes since you have them already. Like James said, the DPF system on the LMM was “primitive” if you will and can lead to issues. Also, the combination of EGR and PCV routed into the intake makes for a rather nasty combination. Recently did a head gasket on my buddy’s (my old one) LBZ with 290k. Bone stock never touched and holy jeeze the cold side and y bridge were scary.

As far as exhaust in the cab, like Tom said double check and make sure connections are tight. All the way up to the turbo. I’d recommend getting rid of the axle dump as well. My truck has a 5” all the way out with nothing but a 12” twister resonator at the end of the front pipe. Virtually silent in the cab but a nice rumble under throttle. Also, these trucks are known to have an ever so slight haze at idle that can give a bit of smell too.

Basically, your deleted LMM is an LBZ engine. And that’s a great thing to have.
 

AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
stacks would def eliminate the in cab smell :woott::woott:



Hahaha hahaha haha ha! I feel like with the sun roof, that has the potential to make it so much worse. Not to mention, I don’t have any more bed space to lose.


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AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
Pretty much covers it.

Could make for a harder re-sell here in phx for a deleted truck (won’t pass emission inspection) but outside the county isn’t an issue as it’s not required.

On an 08, I feel it’s benefitial for the engine to have the delete as the potential to wash a cylinder down from a worn injector is far less. 07.5-10 uses an extra injection cycle on the exhaust stroke to send fuel to the dpf for regen unlike the 11-up trucks.



As for talking about it here, I think guys get a bit confused on where to “draw the line”.

In this case, we are not suggesting a shop to delete the truck and tune it. We are not pushing for a movement of deleting trucks. And the op isn’t here asking vague questions looking to score info on someone/some place for reasons we don’t know.

I don’t see why we can’t help a personal owner see both sides of the situation and let them make their own educated choice on what to do.



I appreciate the advice and opinion, James. As you said, I’m trying to get educated so I can make an informed decision on what to do with my truck going forward.


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RickDLance

Active member
Feb 14, 2007
1,276
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38
Also make sure the downpipe is sealing up at both sends. Some of the "lesser quality ones" leak real bad.
 

AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
I would definitely leave the tunes since you have them already. Like James said, the DPF system on the LMM was “primitive” if you will and can lead to issues. Also, the combination of EGR and PCV routed into the intake makes for a rather nasty combination. Recently did a head gasket on my buddy’s (my old one) LBZ with 290k. Bone stock never touched and holy jeeze the cold side and y bridge were scary.

As far as exhaust in the cab, like Tom said double check and make sure connections are tight. All the way up to the turbo. I’d recommend getting rid of the axle dump as well. My truck has a 5” all the way out with nothing but a 12” twister resonator at the end of the front pipe. Virtually silent in the cab but a nice rumble under throttle. Also, these trucks are known to have an ever so slight haze at idle that can give a bit of smell too.

Basically, your deleted LMM is an LBZ engine. And that’s a great thing to have.
I pulled a Carfax on general principles, and the second owner was the government (indicating that up until at least 151,000 miles, it was bone stock). Should I be worried as to what the inside of everything looks like currently? Did I buy a ticking time bomb?
 

zakkb787

<that’s not me...
Sep 29, 2014
2,340
52
48
Granite Falls NC
I pulled a Carfax on general principles, and the second owner was the government (indicating that up until at least 151,000 miles, it was bone stock). Should I be worried as to what the inside of everything looks like currently? Did I buy a ticking time bomb?

Not a ticking time bomb by any means. Like I said, the truck I worked on had almost 300k on it and ran fine. It just had a lot of gunk built up that we cleaned out before it all went back together. How was your egr deleted? Is it just a blocker plate with everything left intact, a cold side tube to the factory y bridge, or a tube/y bridge combo?

Another thing to check is if they removed the EGR cooler, has the up pipe been welded or replaced? If someone has just stuck a blocker plate on the up pipe with no egr cooler there, it’s going to crack at some point and leak. Mine did this after maybe 10k miles and the bellow wound up broken almost in half. To fix it either take it off, cut below the bellow, and have a cap welded on it, or buy an lb7 type up pipe to replace it with.
 

AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
Not a ticking time bomb by any means. Like I said, the truck I worked on had almost 300k on it and ran fine. It just had a lot of gunk built up that we cleaned out before it all went back together. How was your egr deleted? Is it just a blocker plate with everything left intact, a cold side tube to the factory y bridge, or a tube/y bridge combo?

Another thing to check is if they removed the EGR cooler, has the up pipe been welded or replaced? If someone has just stuck a blocker plate on the up pipe with no egr cooler there, it’s going to crack at some point and leak. Mine did this after maybe 10k miles and the bellow wound up broken almost in half. To fix it either take it off, cut below the bellow, and have a cap welded on it, or buy an lb7 type up pipe to replace it with.
To be perfectly honest, I have no idea how the EGR was deleted and wouldn't know the first thing about figuring that out. I'm a total noob to this whole diesel owner thing, much less the performance enhancement side of it. :confused:
 

zakkb787

<that’s not me...
Sep 29, 2014
2,340
52
48
Granite Falls NC
To be perfectly honest, I have no idea how the EGR was deleted and wouldn't know the first thing about figuring that out. I'm a total noob to this whole diesel owner thing, much less the performance enhancement side of it. :confused:

Try to post a pic of under your hood if you want. It’s easiest to use Tapatalk from your phone to attach a pic. I’d post one of mine and one of my buddy’s but I’m not over there right now
 

AthenaLMM

Swiss Army Wife
Jan 29, 2020
139
4
18
Mesa, AZ
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zakkb787

<that’s not me...
Sep 29, 2014
2,340
52
48
Granite Falls NC
Sooo is that good or bad?


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It’s neither really. It means if for some reason you want or have to go back to stock, there’s nothing on the engine to have to find and put back. If you look at the very back middle of the engine you’ll find the turbo. Just to the left of it you’ll find the egr riser of the up pipe where it bolts to the cooler. If someone has put a blocker plate you’ll see a thin piece of metal between it in addition to the gasket. If there’s no metal, it’s probably just disabled. I’ve heard that under higher pressures the egr can still blow open with pressure, so that’s why some people still put the plate in it. Not going to really hurt either way.