Want an intake manifold but need EGR for CA smog

Discussion in 'Mazdaspeed 3/6 Engine' started by Sand, Jun 10, 2022.

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  1. Sand

    Sand Greenie Member

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    I live in the wonderful golden state of California, where I can't legally pass smog with a single emissions readiness monitor that doesn't pass. But I also have a speed 3 that I am stocking up on parts for a "big" turbo swap on (cst4). I would like to keep all the emissions equipment so that I only have bribe my smog guy to pass me visually.

    I really want to do an aftermarket (Corksport or ST) manifold after hearing how poorly balanced the stock manifold flows, but that requires me to remove the EGR, failing the EGR readiness check. Has anyone found a way to trick the ecu into thinking the EGR is working while it's actually removed?

    Could we simply block off the metal hose that goes from the EGR by the exhaust to the Intake?

    I found this awesome thread (not being sarcastic this time) https://mazdaspeeds.org/index.php?threads/drive-cycles-for-emissions.6026/ in which someone outlined a method of fooling the ecu with a length of vacuum line but people argued the realism of this method.

    Any experience, theories, and discussions welcome. Thanks!

    Another idea... Has anyone tried plumbing the Egr into their intercooler piping?

    I know everyone's first thought is to remove Egr (for good reason)...
     
    Last edited by a moderator: Jun 11, 2022
    Sand, via a mobile device, Jun 10, 2022
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  2. L337TurboZ

    L337TurboZ World Class Truck Squatter Greenie Member

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    Ideally you want the EGR to always be in a full vacuum environment. That's why the EGR tube is always behind the throttle plate.

    You could try and make your own port on one of those manifolds. Basically make a custom EGR to manifold pipe and then a fitting on the manifold to adapt it.

    Another option is to port a stock intake and fully remove the divide between the runners in the manifold itself. On the head ports you'd knife edge the divider between the ports to help smooth the transition into the cylinder head.

    You keep the stock look, it's still CARB "legal" though I use that term loosely.
     
    L337TurboZ, via a Motorola device, Jun 10, 2022
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  3. Sand

    Sand Greenie Member

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    Lol yeah thats what I am going for... Carb """legal"""

    Lots of good ideas. How would you go about making a port on a plastic ST manifold? That point about vacuum makes sense, so does Egr just stay shut if you're making some boost?

    And I have heard a little about porting the stock manifold and the concept makes sense, but this post https://mazdaspeeds.org/index.php?threads/your-intake-manifold-and-you.1271/ seems to indicate there was an even greater flow imbalance after porting the manifold.

    I just don't want one cylinder running leaner than the rest and causing issues, especially if I end up going 6th Port...
     
    Sand, via a mobile device, Jun 11, 2022
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  4. Raider

    Raider Administraider Administrator Platinum Member

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    Stock out for smog testing.
     
    Raider, via an iPhone, Jun 11, 2022
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  5. L337TurboZ

    L337TurboZ World Class Truck Squatter Greenie Member

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    The EGR is shut when the solenoid is off. You want it in a full time vacuum so it pulls the exhaust gasses into the engine. If it was before the throttle plate then extremely hot air would be stagnant and not move as quickly. This would cause excessive heat soaking of the intake system.

    Carbon build up from the EGR is mostly due to unburnt fuel, oil droplets, and the fact nothing is wetting the valves/port to keep the carbon from sticking to it.

    @Raider is right about going fully stock for smog testing. That's the easiest way to ensure you pass.
     
    L337TurboZ, via a Motorola device, Jun 11, 2022
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  6. Speedie6

    Speedie6 Silver Member

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    I know that Cobb has said that they will no longer support bypassing emissions or something to that effect. I do not fully know what that means. People can still use old versions of their software yes? In any case, I have no EGR and no VCTS and no CEL codes with a Cobb AccessPort tune.
     
    Speedie6, via an iPhone, Jun 11, 2022
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  7. Easter Bunny

    Easter Bunny Professional Engineer Motorhead Platinum Member

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    They never actually hid the cel what they did was switch it so the code was always in a not ready state similar to if you had just replaced the battery and the sensors haven't had enough miles to recalibrate. Now they do not put them in it ready so you get the cel. I believe that the change is in new versions of atr so don't update though it may somehow be forced. If you are self tuning with an older version of atr you should still be able to turn them off otherwise you are stuck.

    Not having a visible cel didn't mean that you could pass emissions in states that use obd2 scanners as there is a limit on the number of not ready you can have. Maryland is one California is zero I don't know about other states
     
    Easter Bunny, via a mobile device, Jun 12, 2022
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  8. Speedie6

    Speedie6 Silver Member

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    Thanks for the information. I googled for Texas. Vehicles prior to 2001 can have 2. After 2001 can only have 1
     
    Speedie6, via an iPhone, Jun 12, 2022
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  9. Sand

    Sand Greenie Member

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    Yeah stocking out would be one way to ensure passing but that means I'd have to change my turbo, downpipe, intercooler, and if I get a new intercooler that too.

    Working on cars is fun but redoing work sucks.

    Does anyone know what the ecu does to pass the readiness monitor on the Egr?
     
    Sand, via a mobile device, Jun 12, 2022
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