AFM Delete and California Smog

[Geotrash]

And even if it is tip top they try to find something to charge you extra for in my experience.

My shop has been honest because they know I'm a DIY-er, but they always do offer to do something that they know I won't feel like doing myself, like a brake fluid flush. About half the time I take them up on it.

 

[Dustin Jackson]

My Tahoe passed smog this morning just fine, not sure what the drama is

 

[Marky Dissod]

The smog test in and of itself canNOT test for the presence or absence of V4 mode behavior.

If your accumulated exhaust gases limbo underneath all 3 bars, congratulations.
If not, address your mechanical concerns, or get tuned, or whatever combination.

The test that connects the gubbamint compuduhr to the powertrain control modules canNOT use HPTuna or EFItsalive or any other analysis software to detect if any modules have been tuned.
That test can ONLY verify checksums & checksum verification numbers (basically a checksum of a checksum using multiplication and/or division in addition to addition & subtraction).
Otherwise the gubbamint would simply examine the main spark table or the normal mode shift table to see if either was changed (THE two MOST IMPORTANT tables to tune).

The gubbamint can only check checksums, checksum verification numbers, and exhaust gases.
Proof:
How'd the European gubbamint catch VW group diesels in the act?
They used portable exhaust gas analysers in the trunk.
They did not use the Deutsch equivalent of tuning software to examine or compare the tune with anything or anything else.

I will continue to remain mystified as to why more of you are not yet tuned ...

 

[Dustin Jackson]

@Marky Dissod I don't even think they checked for that, they took my Tahoe back for 5 minutes and then I was done, I think they JUST check the emission monitors. I am curious if I could gut my cats and still pass smog as long as I did it without raising suspicion and keeping my emission monitors looking properly and o2 sensors addressed. but that test will be for a different season lol

 

[Marky Dissod]

... don't even think they checked for that, they took my Tahoe back for 5 minutes and then I was done, I think they JUST check the emission monitors.

You're likely right. I'm just trying to give all these other people who are on one fence or another about getting tuned one more reason to get tuned.

I am curious if I could gut my cats and still pass smog as long as I did it without raising suspicion and keeping my emission monitors looking properly and o2 sensors addressed. but that test will be for a different season.

So far as I know, safest way to get away with this
IFF one were so inclined!
would be to:
open the catalytic converters like clamshells
close the clamshells AFTER installing export pipes - instead of catalytic material, the shell contains a pipe now
(in countries that have no catalytic converter requirement, they use export pipes instead; good luck finding THOSE parts numbers anonymously)
properly installing / re-installing pre-cat O2 sensors & post-cat O2 sensors
deactivating post-car O2 sensors & codes with a proper tune

That same 'proper tune' must also IMPROVE power AND MpG at the same time.
By which I mean: the tune must effectively perform the same function as the catalytic converters.

Those who take emissions sniffer tests with E85 in the tank should have a MUCH easier time passing ...
Once we think of a better source than corn, E85 may NEED to displace gasoline to improve emissions ...

 

[Dustin Jackson]

I've heard of people hammering the cats out with a spike and leaving the outside completely unscathed which would be the way I would try and do it and maybe add another muffler to keep it stealthy

 

[Geotrash]

I always hate the smell of a car with the cats deleted. It gets in my clothes and lingers. I’ve owned a few and I’ll keep the cats for that reason alone.

 

[Marky Dissod]

... hammering the cats out with a spike and leaving the outside completely unscathed ...

A single tap with a knuckle, a hammer / mallet, etc, acoustically gives this away.
Also, hollowing out cats causes pressure wave disturbances which more often than not messes with the engine's power curve.

Catalytic converters are what they are because they have something inside them.
Better to replace the platinum / palladium / rhenuim / rhodium with export pipes.

 

[j91z28d1]

I always hate the smell of a car with the cats deleted. It gets in my clothes and lingers. I’ve owned a few and I’ll keep the cats for that reason alone.

when I got my motorcycle back in 06 it was of the first to have a cat, and of course everyone puts an aftermarket exhaust on, saves weight and looks cleaner. I tossed mine in with the loan and put it on by the 2nd ride. few years later I gave up, couldn't take always smelling like gas fumes. put the cats back on it.

I don't know what it is about this yukon but man you can smell the outside world. Recirculation helps a bit, but I can still smell a ford truck either no cats or just mod motor miss 10 cars ahead of me. non of my other cars do I notice it like this thing. once it's in the cabin, it's hard to get out too.

 

[Doubeleive]

Thanks for the input everyone, good to get different perspective and opinions.

When the time comes I'll just go to my normal smog guy and see what happens, I think he's a safe spot to test this at.

I guess the fear mongering of the auto shop guy from yesterday spooked me a bit but his information doesn't exactly align with what I've found in my own experience and research.

Quick side note - Jasper engines does make a CARB certified AFM deleted motor for these but that's not relevant.

Those guys were full of it, if worse comes to worse you buy a used unmarried canned carb certified tuner, hypertech, etc and put that on it to pass smog and then put the bb tune back on. I did it, it passed. Relax