ACE Header Independent Testing Results and Review - 199.6WHP on CA 91 Octane

[Foobar]

Originally Posted by MaximeT

Not having a CEL is one thing. But the ECU making a positive reply to the cat diagnosis completion is another. It's a lot harder to do without manufacturer support. Cat diagnosis calibration is an engineer full time job.
In fact this job is not done by the car manufacturer, but by the ECU/injection system manufacturer.

Is it not possible to cheat inspection in the US ?
I plan on going FI with my car in France, which is illegal and will drive without the local MOT (as I drive on the road from home to the track only, it's not a DD)
Police only arrest crapy looking cars out there (or sadly, people with dark skin)

If I want, I can buy a MOT sticker from a MOT agent that just want easy money (without seeing my car, obviously)

In the US, most states' emissions check involves testing the readiness monitors via OBD2. To that end, you simply disable the DTC in your tune using your favorite ROM editor and flash it to the ECU.

Some states include a visual inspection of the OEM emissions gear. In that case, they'll see the aftermarket replacements and fail it.

Other states perform a sniffer test, depending on the equipment used and the tune involved, you may or may not pass.

[MaximeT]

If you disable the DTC, the readiness will stay to 0. Or do you have a way to set it to 1 ?

[CSG Mike]

Originally Posted by MaximeT

If you disable the DTC, the readiness will stay to 0. Or do you have a way to set it to 1 ?

Contact your tuner

[MaximeT]

Originally Posted by CSG Mike

Contact your tuner

Was just a question, just curious


Edit : you don't want to work with french tuners

[OkieSnuffBox]

Originally Posted by churchx

Indeed, i just empirically guessed

Seriously, just stop. It's obvious you really have no idea what you're talking about.

Empirically guessed? Really?




Go look it up chief.

[Freude am Fahren]

You all need to move to Florida. Inspections? Emission testing? CARB? 91 octane? What are those?

[AlexBinJackson]

Originally Posted by Freude am Fahren

You all need to move to Florida. Inspections? Emission testing? CARB? 91 octane? What are those?

Lol people in California love to over react . It's not too bad to replace the headers before testing and reflashing back to stock. Just wait for carb (it's coming to you) and what is 91 I'm on e85 😋

[CSG Mike]

Originally Posted by AlexBinJackson

Lol people in California love to over react . It's not too bad to replace the headers before testing and reflashing back to stock. Just wait for carb (it's coming to you) and what is 91 I'm on e85 😋

If you don't need to go on the sniffer....

[Coheed]

Originally Posted by AlexBinJackson

Lol people in California love to over react . It's not too bad to replace the headers before testing and reflashing back to stock. Just wait for carb (it's coming to you) and what is 91 I'm on e85 😋

This is so true. In the past 10 years, half the counties that didn't require testing now require testing in Utah. Diesels need testing, and chemicals were just switched over to low VOC CARB regulations.

If you don't have CARB now, you might be ok for a while. Where I'm at, CARB isn't a requirement, but it may end up being so in a couple years.

[enivid]

Originally Posted by Coheed

This is so true. In the past 10 years, half the counties that didn't require testing now require testing in Utah. Diesels need testing, and chemicals were just switched over to low VOC CARB regulations.

If you don't have CARB now, you might be ok for a while. Where I'm at, CARB isn't a requirement, but it may end up being so in a couple years.

I don't know of any modified 86 in Utah that has failed emissions yet.

[MaximeT]

If you still have one cat and 14,7 AFR, you should be fine with a warm engine.

[Shankenstein]

Originally Posted by churchx

Indeed, i just empirically guessed how it works...

I'm far from an expert, but my understanding is that O2 sensors read the partial pressure of oxygen in the exhaust stream, when compared to a reference air sample.

The partial pressure gets translated into a metric of combustion completeness (lambda - the normalized AFR).

The ECU begins with a target ideal AFR and "learns" the best AFR for your fuel, based on a recursive algorithm. Although you want to be near complete combustion, most ECUs try to cycle between lean and rich operation to keep the catalyst operating efficiently. The ECU spits out a target AFR at this point.

By combining the learned AFR of your fuel and the measured lambda, you get an estimate of actual AFR. The ECU compares the actual and target AFRs, which is useful feedback for the next combustion event. Correction is usually on the injector pulsewidth (since it's fast), but you can adjust the throttle or VVTI angles to manipulate the air flow (LOAD).

Regarding catalysts, the catalyst flow, health, and efficiency are modelled. Flow is simple enough, it's a fixed volume, with some flow restriction. 1st order system w. small time delay in the sensors. From a health and efficiency perspective, they estimate temperature and oxygen storage states. If you're actively storing and releasing large amounts of oxygen, the catalyst can be 90%+ efficient.

With an efficiency estimate and a time estimate... you can follow a volume of exhaust from the UEGO (upstream linear O2 sensor) to the HEGO (downstream switching-type O2). The metric for catalyst health isn't something I know much about... but going through the readiness cycle (lots of different driving situations) will help to guarantee that the models used to generate the health metric are accurate.

[churchx]

Thanks for actually writing info instead of having fun at my expense. It doesn't say much though how those aftermarket sensor spacers manipulate/affect readings for secondary placement or how PTuning's headers can claim no CELs when it looks normal bungs in yet another catless header, or how to affect readings to fool ecu in more precise manner.

[steve99]

Originally Posted by churchx

Thanks for actually writing info instead of having fun at my expense. It doesn't say much though how those aftermarket sensor spacers manipulate/affect readings for secondary placement or how PTuning's headers can claim no CELs when it looks normal bungs in yet another catless header, or how to affect readings to fool ecu in more precise manner.

ptuning and ft86 speed factoy (catted header) can claim their header will not cause cel but that does not mean it wont trigger the cel in the real world.

The truth is some people might not trigger it and some will depending on luck mods and tune and fuel. The ecu will be looking for specific reading from both front and rear 02 sensors and apply some weird algorythm to the reaing over time, if the reading fall outside what the ecu algoythm is looking for over time then bingo you get cel.

its same with o2 spacers sometimes they work sometimes they dont, sometimes they just extend the time it takes cel to appear.

Ask both those manufactures if they will give you your money back if it trigger cel without disabling codes ect in tune and i doubt they will say yeah sure we will do full refund