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Discussion Starter #1
I have to get a smog test on the truck in the sig. I will program it back to stock but do I need to install a muffler to pass? I still have the cat on.
Thanks
Des
 

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I believe this year you will be ok. Next year, will be a different story. All they are doing is a visual testing and the stomp test. looking for smoke a WOT. In 2012, they will have the new smog machines and they will be able to see what comes out the pipe. With out the muffler your Nox will be high and not pass.
 

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muffler will not change the nox, the cat will, you wont need the muffler, as long as you still have all your EGR equipment and your cat in place (not punched out) you will be ok, stock intake or with carb approved labels. Good luck there... When is your test?
 

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muffler will not change the nox, the cat will, you wont need the muffler, as long as you still have all your EGR equipment and your cat in place (not punched out) you will be ok, stock intake or with carb approved labels. Good luck there... When is your test?
Yes it does. The egr needs some back pressure in order to work correctly. I know this because I had a calr FAIL do to this problem. If the EGR isn't working correctly the nox will be vary high.
 

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Stuck in Commiefornia...
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The cat and the VGT turbo provide all the backpressure you need on a 6.0 to make the EGR function. If you had a straight through performance muffler or a straight pipe there is no difference.

A muffler is required by law, but the definition of what constitutes a muffler is pretty vague. You could argue that the turbo is a muffler, and you would be right, but the smog tech doesn't have to accept your argument. Your best bet is to have something resembling a muffler on the truck and you'll have no issue.

Or play dumb....
 

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Discussion Starter #6
I have an AFE exhast system and it came with a new muffler, I just had a delete pipe made. I think i will just throw the muff on just because. Not sure where in going to take it yet I have until the end of Feb to get it done, knowing me and most of you, guys / gals we wait until the last minute. I shouldn't without any late fees my reg is only $550! :beer If you are having that damn front end wobble, it can be solved!
 

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2005 smogged in August- no problem. I have tb MagnFlow 4" exhaust with muffler and cat inplace. AFE II. the guy looked at everything- no problem.
 

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I have to get a smog test on the truck in the sig. I will program it back to stock but do I need to install a muffler to pass? I still have the cat on.
Thanks
Des
No. I smoged my truck. you need the stock tuning, no codes, and keep the cat on.

The tuning is mainly to keep the smoke down. If you do not have any smoke then you can keep the tuning on there. They just dont want to see any smoke.
 

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Stuck in Commiefornia...
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Something new to add; I was at the dealership buying new batteries the other morning. (I got 6 years out of Motorcraft batteries, and I've always had good luck with them). Anyway, one of the diesel techs is in there while I'm there and he's ordering a down pipe and cat for a 6.0L. I pop off about the owner of the truck needing to put up signs for a lost cat and he comes back with "No, it just failed the visual because it had an aftermarket down pipe and they modified the cat to fit the larger pipe. There was no CARB Number on the downpipe dot the smog guy took his money and failed him."

The smog Nazis have apparently sent out bulletins that state any modification to the exhaust forward of the cat must be done with certified parts. This is going to get interesting...
 

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Missing-modified-disconnected. Those are the 3 things they will look for on a visual. The B.A.R. will also send out undercover tampered vehicles as well to smog check stations to see if techs or a facility is passing illegal smog inspections. The fines are astronomical if one is caught, even to the extent of shutting a business down permanetly and or jail time. This is the threat that smog techs have to operate under. This is going to be a real headache for heavily modded trucks. Theoretically, any exhaust mod that lowers backpressure in some way could potentially affect egr and nox emissions, at least thats how CARB and the B.A.R. see it. I was a smog tech at a large SoCal dealership for many years before moving out of CA to PacNorthwest. That CARB compliant sticker or engraving/stamp is going to be very important on any modded parts. I just hope other states like mine don't follow the overly strict CA emission standards.

Harry
 
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