AFM Delete and California Smog

[Dustin Jackson]

Last summer I mechanically removed the AFM from my motor and used Black Bear to tune out the AFM from the computer but I haven’t actually had to smog it yet but I assume it will be next year or so. I took it to my smog guy and told him what I had done to my tahoe (he’s a Chevy guy and is aware of the AFM delete scene) and asked him if he thought it would smog, he plugged in a OBD tester and I think he looked at the engine monitors and said “it should pass no problem”

Out of curiosity I stopped by an auto shop at the edge of my neighborhood with a couple chevys in the lot and a jasper engine sign out front.

So I stop in and find a couple mechanics and I shoot the shit with them for a bit and ask them about AFM deletes and how to navigate smog and they told me the only way I can smog it would be to buy a new PCM and reprogram my keys to it and then buy a Diablo tuner and use that to tune AFM out.

Following with their logic I asked them if I could just flash my factory tune back onto my ECU and then buy the Diablo tuner and turn off AFM that way to pass smog but they were pretty adamant that my ECU is not usable anymore and if I tried to smog with my ECU that I would get flagged and all kinds of bad shit would happen.

One mechanic was saying that the Diablo tune doesn’t flash the ECU he said “it just goes in and flips AFM off” so that the smog shop doesn’t detect the ECU has been modified.

In my situation I tuned my Tahoe with a black bear autocal and in this tune I have more modifications other than turning AFM off, I have raised the RPM a little bit and more throttle response. I don’t know how to check if the ECU has been modified but I imagine if someone checked it would show that it’s been modified.

Now I don’t fully understand how an ECU works in this context to understand what those guys were saying entirely, could you guys shed some light on the subject here? I’ve got my smog guy telling me I should be good but now I have these guys saying I’ll basically go to prison if I try to smog it.

 

[swathdiver]

Last summer I mechanically removed the AFM from my motor and used Black Bear to tune out the AFM from the computer but I haven’t actually had to smog it yet but I assume it will be next year or so. I took it to my smog guy and told him what I had done to my tahoe (he’s a Chevy guy and is aware of the AFM delete scene) and asked him if he thought it would smog, he plugged in a OBD tester and I think he looked at the engine monitors and said “it should pass no problem”

@BlackBearPerf says that their changes are not detectable.

 

[Marky Dissod]

STOP WORRYING.
If Black Bear says their changes / tunes are undetectable, I believe them - specifically because the checksums and CheckSum Verification Numbers are always addressed by a proper tune. (Go ask a mathematician what a checksum / CVN is; I get it, but my explanation will likely be inadequate.)
If this were not the case, hundreds of thousands of 'tunes' would have already been flagged by Kalephonyuh's CARB.

I'd be more concerned about passing the butt-sniffer test.
Even so, a proper tune should have enough DFCO to slide under the HC / CO / NOx thresholds.

 

[Dustin Jackson]

I see, so basically when the software is inspected it looks unmodified?

My smog guy said he doesn't even sniff the tailpipes on vehicles this "new" he would just check for check engine lights and making sure the emission monitors are set, which both pass and even he tested it himself. Also I haven't done any modifications to affect the emission systems.

I just assumed there had to be more involved in a smog check than checking for codes and emission monitors.

 

[Marky Dissod]

... when the software is inspected it looks unmodified?

When you say 'the software', you mean the state emissions inspection software?
Yes, it looks unmodified, because it was modified in such a way as to appear unmodified to a gov't computer that only checks 'Check Engine' codes and emissions readiness states.

Those arses rolling coal, on the other hand, called way too much attention upon themselves.
Yet even so, gov't computers are only - presently - verifying checksums & checksum verification numbers (besides codes and monitors).
Luckily, proper tuning software also 'tunes' checksums and checksum verification numbers so as to be undetectable.

How do you think VolksWagen Aktiengesellschaft got away with OE tunes that knew the difference between vehicular treadmills and actual roads for so many years?
Emissions inspectors are not perusing each vehicle's tune with HPTuna or EFit'salive ... yet ...

 

[petethepug]

Just have a smog shop do the test offline. You’ll know right away and no one else will be the wiser.

Good thinking on being preemptive though.

 

[Airman68]

Just the fact that the government is looking at your ECU program would be enough for me to get the heck out of there! Seriously... WTH is it their business? if you pass, who cares how you did it.

 

[Marky Dissod]

Just the fact that the government is looking at your ECU program ...

The gubbamint only looks at checksums and checksum verification numbers - and THEN ONLY of vehicles suspected by the CARB or the EPA.
They are most certainly NOT looking at entire programs - just checksums & CVNs.

 

[BlackBearPerf]

While we cannot comment on any smog testing really, we do recommend the same as if you were taking the vehicle back to the dealer. We recommend using your AutoCal to go back to factory settings and put a few miles of driving in before your inspection. We used to live in California (we have since escaped!) and of course, had our vehicles tuned and we had no issues. Without going into detail, we use every effort to ensure that there is no trace of the tune when returned back to stock.

 

[Geotrash]

While we cannot comment on any smog testing really, we do recommend the same as if you were taking the vehicle back to the dealer. We recommend using your AutoCal to go back to factory settings and put a few miles of driving in before your inspection. We used to live in California (we have since escaped!) and of course, had our vehicles tuned and we had no issues. Without going into detail, we use every effort to ensure that there is no trace of the tune when returned back to stock.

Spot on, but that strategy won't work if one has an aftermarket cam - especially one that deletes DoD and VVT. Restoring the factory tune in that scenario could cause real problems with drivability and may not even run.

I love my BB tune though and am grateful to live in a non-emission test area of a state that hasn't signed on to CARB standards.

My sense of what people are wondering is whether a BB tuned engine with an aftermarket DoD-delete cam would pass a CARB test that uses a checksum of some kind to determine the originality of the tune. My research suggests that it would fail the checksum test, even if none of the ignition and timing parameters were changed. But then again, nothing I've read is really conclusive. Some say that the tune would only fail the test if the checksum falls out of a range of acceptable values, indicating a really significant change, such as an EGR delete on a diesel for rolling coal. But I can't find anything more conclusive.

 

[donjetman]

Here where I live in TX not only did the state get rid of smog test that was in only the big blue cities, but I hear tale the safety inspection is going away.

 

[BlackBearPerf]

Absolutely correct. Definitely would not be able to go back to stock with an aftermarket DOD-delete cam. Most likely would not be able to drive it. If you are in California, you would have to make sure the cam is CARB certified. I had to show my carb sticker on my CAI each inspection. We have a lot of customers in states or localities that require inspections and their vehicles are modified. We haven't heard any feedback that they have failed due to the tune so that's good news.

 

[Dustin Jackson]

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.

 

[j91z28d1]

Here where I live in TX not only did the state get rid of smog test that was in only the big blue cities, but I hear tale the safety inspection is going away.

yeah, they finally passed the vote to get rid of the useless check but to do it after 3 year's of failing they had to keep the 7$ fee built in. scum bags.

Austin is keeping its smog test and San Antonio is adding it the next year. I don't know if it's within the city limits or county thing. not sure about the rest of the big cities.

this and the property tax scam, this state annoys me. some times I miss Louisiana lol.

 

[Dustin Jackson]

@j91z28d1 @donjetman Interesting, in California we don't have safety inspections only smog checks. Based on some things I've seen on the older chevy groups I'd say a safety check isn't unreasonable in the northern states because people will drive a truck with a rusted in half frame. I agree that the government should be as non intrusive as possible but in some cases some forced common sense is needed.

 

[j91z28d1]

@j91z28d1 @donjetman Interesting, in California we don't have safety inspections only smog checks. Based on some things I've seen on the older chevy groups I'd say a safety check isn't unreasonable in the northern states because people will drive a truck with a rusted in half frame. I agree that the government should be as non intrusive as possible but in some cases some forced common sense is needed.

oh yeah. I'm mostly fine with it, but things don't rust here and they honestly don't check anything. for my cars I've watched them, they walk out, turn the head lights on, check the turn signal. record the mileage and come back in. it's not like they put them on a lift or something. I hear they are supposed to check the brakes, but I've never seen it. it's mostly just annoying.

I've seen some sketchy stuff on the road, but I also remember as a kid my mom had a old 68 chevy that smoked blue pretty bad. a cop pulled her over and gave her a fix it ticket. long before any smog or inspection was needed, cops can just keep an eye out for a junker on the road that looks unsafe and hand a fix it ticket. then you just needed to stop by the dmv with a receipt for some parts. life was easier.

I was very young and I seem to remember we took the car to junk yard instead of putting an engine in it.

 

[Geotrash]

There have been studies done for years that show no appreciable increase in vehicle failure-related accidents in states that have mandatory vs those that don't. Here in Virginia, I have to waste 4 good mornings and afternoons every year dropping off and picking up one of our cars for an inspection that it will pass every single time, without fail. With modern cars, the whole safety and emissions inspection schemes are rackets. Just like state-run liquor stores. Oh here I go getting all pi55ed off...

 

[Dustin Jackson]

@Geotrash 4 inspections per 1 year?!

 

[Geotrash]

@Geotrash 4 inspections per 1 year?!

4 cars x 1 inspection each per year. next one is coming up on Monday morning for the LR2. And I know it's 100% tip-top. Waste of time.

 

[89Suburban]

4 cars x 1 inspection each per year. next one is coming up on Monday morning for the LR2. And I know it's 100% tip-top. Waste of time.

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