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If you want to fix this just put a rising rate regulator on your fuel rail. Either that or an adjustable one. This will allow you to let more fuel then the stock regulator will allow. Of course this will also increase your injectors duty cycle, but most manufacturers do around 50-60% duty cycle. Rule of thumb is not to let them go about 80%.

This should fix the problem and I believe APEXi selles there for like 215.
 

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CEL being turned on because the ECU sense fuel/air ratio is out of "factory spec"; if the tolerance level of the "factory threshold" is set too low, CEL warning will be turned on even it's not leaning out... That may be the reason why Injen still releasing the intake.
 

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Looks like this applies to the Mazda6 S (V6) intake only, though apparently the ECU on the 6 (& apparently the 3) are very sensitive to the fuel trims going out of whack.

I remember the AEM guy was making a big deal about this, saying that he was able to get more power out of different intake designs but that the designs messed up the fuel ratio, so he found a different design, that made less power, but kept the fuel trims close to stock.

Also, I don't think that this is an issue of inadequate fuel delivery, so I don't think a beefed up fuel system would help, what it seems is that the intake design is causing the MAFS to register that there is less air going into the engine than there actually is, so the ECU sends less fuel (too little for the actual airflow) and the result is a lean burn detected by the o2 sensors. It seems that if one could adjust the signal from the MAFS to make the ECU think there is more air coming in you could correct this problem, though youd have to really know what you are doing, if you screw it up and end up running rich that will be just as bad (perhaps worse) than running lean.
 

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kenstyle said:
If you want to fix this just put a rising rate regulator on your fuel rail. Either that or an adjustable one. This will allow you to let more fuel then the stock regulator will allow. Of course this will also increase your injectors duty cycle, but most manufacturers do around 50-60% duty cycle. Rule of thumb is not to let them go about 80%.

This should fix the problem and I believe APEXi selles there for like 215.
Does anyone know of the 3 uses a returnless fuel system? If so, then a rising rate regulator won't do any good cause the fuel line has a fix constant fuel pressure and since there is no return line, there is nothing to restrict to rise the fuel pressure. Also, it's the first time I hear adding a rising rate will increase duty cycle of the injectors. I always thought duty cycle is controlled by the fuel map inside the ecu. Correct me if I'm wrong please.
 

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Ya injen wiil try to redesign it the only resean they sell the one for the 6 that causes a cel is because it made like 20hp for the v6 and there was a very high demand for it when they took it off the shelves so now they seal it with a warning label about the CEL. The CEL is not causing any damage and the only time the car runs lean or actually receives a lean siganl is at idle and there is nothing to worry about there because its just the ECU being overly picky. On anothe rnot I have the injen in my 6i havent had a single CEL
 

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Why not use that warranty and let the dealer fix it? Or is it so heavily modified they'll laugh at you when you take it in? :lol:
 

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Well since the mod caused the problem I'd say they would be justified in not fixing it.

On a related not, I can picture if Mazda hears about this that if anyone comes into a dealer with a CEL and has an Intake the dealer will say it's the Intake's fault.

Thanks Injen!!
 

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When Injen tested the intake on my mz3, they said they were having a lot of problems because the engine was so sensitive with the intake tube because either the diameter of the tube was too big or too small, so they had to keep changing the diameter of the tube. but everything should be okay for us 3 owners, all they're doing now is getting a patent for the CAI.
 

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First of all everyone will tell you when you shove more air into the cylinders you need more fuel. Go to any performance shop or mechanic and they will tell you a way to get more feul into the rail is changing the regulator for a higher capacity one.

Second duty cycle is controlled by the amount of fuel your car will be allowed to send. Right now because there is more air then fuel it's leaning out. Because it's running lean the o2 sensors are sending an error signal to the ECU. There are several ways to increase fuel rate:

1. Fuel pump
2. Regulator
3. ECU
4. Injectors

When your ECU is being told there is more air then fuel it will try to increase. Geuss what's choking it off? The regulator.

Hasn't anyone seen the Horsepower show where the add and intake to a Honda Civic. Gee what else did they add an f-ing rising regulator. Same thing for there mustang and GM projects.
 
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