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Has anyone ever pounded the DPF out of the casing for a DPF delete?

13K views 32 replies 15 participants last post by  mizterwizard 
#1 ·
So I need to smog the tuck where I live but don't wanna have to swap exhausts every time I take it to get smogged which they will red flag if they see that there is no DPF.
Has anyone pounded the DPF outta the casing?
I've done it to CATS on motorcycles, not familiar with DPF's though.
I saw a video where some guy cut a hole in the side of a dpf and chizzled it out and welded the plate he cut off back on. I don't wanna do that.
is it possible to just take my air hammer and pound the dpf out to basically make a big empty casing creating a dpf delete but looking oem? then put on a dpf back exhaust and should be good to go.
thought?
concerns?
anybody done it?
 
#2 ·
I would suggest not doing to the one that is on the truck, OBD-2 emissions testing is not too far into the distant future and without the sensors reading correctly you'll fail. Sometimes you can find them cheap on here or craigslist.
 
#3 ·
Just get a delete pipe and keep the DPF intact. Just swap them when you need to get tested, gotta go back to stock tuning as well.
 
#4 ·
You can get a DPF delete pipe that has the 4 & 3 bolt flanges, makes for a easy R & R.
 
#5 ·
Is stock pipe 4"?
Maybe I will just get the delete pipe and a dpf back exhaust.
Get 1 of those on the fly switches and have the lowest settig the factory setting for smog.
 
#7 ·
I'm not sure if you can have emissions present and deleted tunes on the same dsp5, I could be wrong but you may need to invest in a v2 and keep your stock tune on it as well as you deleted dsp5
 
#8 ·
On my work trucks I just cut the dpf in half length wise and gut it then weld it back together. Don't get bugged about emmisions up north here though. I just like the sleeper look and it's still nice and quiet to work around.
 
#10 · (Edited)
If you go back and read the replies I'm pretty sure one mentioned he did something like what your wanting to do.
You'll also read a few that suggested to just buy a DPF delete pipe that bolts right up in place of the DPF with 3 & 4 bolt flanges.

And then store your DPF completely intacked somewhere in case you ever sell or trade in the truck and have to make it emmisions compliant again in order to do that.

I'm sure if you do a search over the past several years, you'll find several did what you want to do and/or trashed the DPF after doing a full exhaust then after a few years panicly looking for a used DPF that they need to buy and put back on in order to pass emissions or sell.

Because they don't want to have to shell out $1500+ or so bucks to buy a new one from the dealer.
This is where Forest Gummp's famous saying comes to play "Stupid is Stupid Does".

It's totally up to you on how you want to go about doing this.
Eventually any emissions person with a brain can tell/smell you don't have what's needed to legally pass.
 
#11 ·
What type of testing do they do in Idaho?

in Wisconsin we have a test where they only plug into the OBD2 port and check readiness status. I am DPF delete with Kory Willis tunes and passed the check, they didn't do a visual inspection (oil change place) so they don't really know what to look for.
 
#18 ·
Curious about this, the readiness state was ok with the delete tunes? I didn't think that would be the case 'dunno;

If so I am thinking about doing something along these lines to avoid changing everything out every 2 years. What kind of scanner do you need to see the readiness state? Will an Autocal show this? I have Innova 3100 that supposedly shows this info via 3 LED lights, just not sure if it's the same the state would use.
 
#12 ·
I think I have an idea.
I'm gonna go to pick n pull, LKQ, or some other parts yard type of place, buy a dpf and gut that. It'll be cheaper and if I'm lucky may not have to switch for emissions. Also if the dpf casing ends up FUBAR after messing with it, no big loss.
Any objections or foreseen problems?
 
#13 ·
I haven't had a diesel loving in Idaho yet, but I've heard they do a visual for cat and dog, anything else idk. Haven't been through the test yet
 
#14 · (Edited)
At this time some states are not as strick as others, but the way the EPA is clamping down on these tuners doing emissions deletes in the USA, someday all states and counties just might test all diesels to the limit.
That's the fear we all face in the possible future, do as you feel comfortable with doing.

In Arizona we only have testing in Maricopa & Pinal counties at this time and at a actual Arizona Emissions Testing Station, no lube or private testing. A few are smart and know what they are testing and we do have a few dummies.
 
#16 ·
Gutted my DPF and Kitty. Looks completely stock and EFI took care of the codes. Pass smog test everytime. A little louder and smells a tad more like a diesel. My .02
 
#17 · (Edited)
Gutted my DPF and Kitty. Looks completely stock and EFI took care of the codes. Pass smog test everytime. A little louder and smells a tad more like a diesel. My .02
IF Maricopa County upgrades the 30 year old system in current use to the new CARB OBD-II test we're in trouble and there are more ways to turn off and set emissions readiness monitor's on the LMM tune than my LBZ. I would suggest taking your truck in to have tested at the maximum 90 days prior in the coming years to be sure the County has not upgraded, this will give time to find a fix...

In addition any new emissions program implemented in the US will be using this system as the EPA has adopted CARB procedures across the US. I suspect in the next 5 years this site and others like it will be littered with guys looking for emissions parts they have removed from their trucks, so save your old stuff. I might also add that if you sell a deleted vehicle you the person that deleted it is responsible not the new owner and EPA/CARB can come after you. Trading in a vehicle to a dealership that has been tampered with can also have repercussions if they choose not to wholesale the vehicle out of there inventory and sell on their lot, again you are responsible.

I also see guys here in town deleting newer trucks completely and see the parts on craigslist. Why, more than likely they will sell the vehicle before emissions test is required here in Maricopa county as new vehicle's are not tested for 5 years from the date of original purchase or registration..

Just be prepared for future changes and have a backup plan...:thumb
 
#21 ·
So how hard is it to pound out the insides of these. It sounds like a good idea to keep it looking stock. Here is montana we don't have the testing but our highway patrols are starting to look under vehicles for visual inspections and who knows if there smart enough to know what to look for.
 
#22 ·
I did it this weekend.it was like butter compared to a cat.
I will post a thread with pics after all complete.
I'm in the process of welding it back together.
 
#23 ·
Just curious, those of you who live in areas where emissions testing is in place, what do they look for in pre-DEF/DPF trucks? We don't have testing in my area-yet, but all the stuff fell out of the CAT on my LLY and EGR has been EFI'd, although everything is still intact. I see a lot of guys driving around with deleted LLYs & LBZs and wonder if if the EPA folks are going to be bothering them some day...
 
#26 ·
In Ada county Idaho (Boise) from the paper I got when I just got it smogged (prior to finishing the pounded out dpf and flashing efi live) the guy said they
Make sure there are no error codes.
They hook up a computer to the obd2 port solely for registering rpm on their computer.
It captures soot level at idle and then it had him floor it to just over 2000 rpms
And it takes the soot reading then. Max is 40, mine came back at .1 with my dog
Kinda showing how restrictive it is.
He also visually peeked real quick with a mirror that my cat and dog were there.
Never opened up the hood.
That's it.
Once I finish welding back together the used dpf I got so it basically is a straight pipe
I'm gonna go back and pay for a test just to see the difference with a straight pipe and efi live.

I wonder what the best tune would be to use to try to get the least amount of soot.......
 
#24 · (Edited)
As far as enforcement goes, there isn't any one to do it unless you have mandated testing. In that case you just have to pass the test. It's not like the EPA is going to send federal marshals around to haul you butt off to prison for polluting the air.

Have you seen anyone rolling coal? They might as well be using a bull horn to say, "I have deleted my smog controls and I don't care who knows." Actually I think rolling coal is even more overt than a bull horn. Nobody is arresting those guys. They wouldn't get any sympathy from me if they did get arrested though.

The problem with deleting any emissions control is that the EPA has mandated since 1996 that all vehicles test for proper emissions function. The manufacturer has to certify that the vehicle not only is clean from the factory but also down the road. The EPA stopped taking their word for it long ago (because they lied too much). If you monkey with the smog stuff the computer will figure it out and set a code. The way around it is to reprogram the computer to either stop testing or ignore the result. We call this "tuning".

If you "tune" your truck and then take it in for testing the test will fail because the tune will be detected. The manufacturers ensure that this is possible because they also want to know if you have tweaked your truck so that they can void your warranty. If you don't tune the truck then the test will fail because there will be a code set for the deleted equipment. The advantage to leaving the smog stuff on the truck and just turning it off with a tune is that you can restore factory tuning to get an emissions test and then return to the disabled tune minutes later. This doesn't work with DPF because if you shut it off the filter will just plug up and kill your performance unless it can regenerate.

The test the computer does for a DPF is to measure the pressure difference between the inlet and outlet of the filter. It should be within a certain range. If it is too high the computer will command a regen. If it regens a couple of times and the pressure difference remains high it will set a code for a defective DPF and probably go into limp mode. On the other hand, if the difference is too low, as it would be with a gutted DPF, then it will assume that the pressure sensor is bad and set a code for that. The fix for this is to turn off the code with a tune.

To get past real testing you would have to return the system to stock, more or less. Fortunately many of us don't have to do testing. For those of us who live outside the reach of Big Brother, it isn't really necessary to consider enforcement. It is possible that a particularly enthusiastic state policeman would have a look under your truck (because they don't really have anything else to do) but I can't imagine even the most radical cop carrying around a scanner and testing trucks on the road. The worst that would likely happen is you would get a ticket that would require you to get it inspected or pay a fine. If that happened then you would restore the factory setup, get tested, show the judge the test result and then redelete. I suppose if you got lippy with the cop he could have your truck impounded but then if you are stupid enough to mouth off to a cop you probably deserve to have a bad day.

In the real world, if you aren't rolling coal, doing burnouts between lights or doing something else antisocial, you probably have nothing to worry about. Keep it clean, under control and play nice with others and you will not have to deal with the complications the EPA loves to throw at us.

Some things I'd like to add. I am now coughing because I breathed some dust from a cat that came apart on its own and wound up plugging the pipe down stream. Be careful when "inspecting" for a plugged exhaust and removing the obstruction. Wear a mask.

Don't destroy any expensive emissions parts. You never know when you will have to put them back into service, even if it is just for a day or two. Get junk yard parts to substitute in for your good stuff. It costs a few bucks but it could be a lot cheaper than new parts or a fine.

It has been suggested earlier in this thread that junk yards aren't supposed to sell emissions parts. I've never had a problem except for converters. I'd leave the converter in place because it doesn't hurt much, if any, and it is potentially very expensive to replace if you gut it to go stealth. If you aren't worried about people looking under your truck then just do a delete pipe and keep the deleted stuff in the shed, just-in-case.
 
#29 ·
Be cautious if you do a retest after you passed and you have to comply with emissions, if you fail they just might stick to the failing on the 2nd test and affect your registeration, even if you passed the first time and paying for the second retest.

You might be better off and just wait and worry about it the next time your suppose to do testing.
 
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#30 ·
i smog in California and for 1998 and up diesels they plug in to obdII and check for readiness status. a "not supported" pid will fail the test automatically. it would be really cool if the tuners changed the perimeters of the readiness to always say "completed" then we would have no issues with modified trucks. i personally have my cat and dpf gutted to look stock for CHP purposes. they are getting super strict and handing out modified emissions tickets.
 
#31 ·
[snip] it would be really cool if the tuners changed the perimeters of the readiness to always say "completed" then we would have no issues with modified trucks. [snip]
Yes please.
 
#32 ·
For searching purposes in the future, check out my signature line.
I cored it out.
Was a piece of cake.
 
#33 ·
The smog guys are getting smarter all the time. There is even a proposal to have smog testers along the roadside to check the emissions of vehicles as they drive past. Sort of like the radar trailers you see parked around. If your car failed then they would take your picture and send you a ticket just like a speeding ticket. I understand the technology is in place to do the remote scanning. OBDIII is supposed to include a radio link so that the technician doesn't have to make a physical connection to the vehicle to scan it, like bluetooth. Of course it also means that anyone who wants to can scan your vehicle for what ever reason they have. OnStar any one?

As the smog testing gets more invasive we will just have to get trickier. Eventually we will have electric vehicles with no smog testing but then we will be hopping up the controllers to get more amps to the traction motors, which will waste energy, which was generated by green house gas emitting power plants, so it's a smog thing according to the D.C. overlords. They will be scanning our vehicles for over current and issuing smog tickets. To a guy with a probe, everything is an exhaust pipe.
 
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