My guess is that the intake has thrown your MAF out of calibration. The MAF is what tells the ECU how much air is going into the engine, and this measurement is used to calculate how much fuel to squirt into the combustion chamber.
AEM/Mazdaspeed put the MAF sensor after a bend in their intake design and use too large of a diameter pipe. The too-large pipe causes the MAF to report overall lower air flow. This leans out the air/fuel ratio since the engine is getting more air than the MAF says to expect. The ECU will see this, though, since it monitors the fuel ratios via an O2 sensor, and it will quickly try to compensate by learning new fuel trims (fuel adjustments). Unfortunately, the required corrections aren't linear, and the ECU is not capable of making elaborate corrections. Furthermore, the bend in the intake pipe causes turbulence in the incoming air, making things even less predictable. When the ECU sees its own fuel trims off by large margins for a certain period of time, it will throw a CEL. This most frequently happens in stop-and-go traffic when the ECU is constantly trying to optimize its fuel trims for idling, then driving, then idling again.
Unfortunately, AEM/Mazdaspeed intakes threw the same CEL on other Mazdas, too, for all the same reasons. It's a shame as it really sours the Mazdaspeed brand. If this intake is throwing "lean" codes, then that means it can lose its Carb certification, too- but as a Canadian, I doubt you care.
Your options are to:
- Reset your ECU and hope it doesn't happen again.
- Buy an air/fuel tuner and lots of dyno time to recalibrate your intake. This is expensive and difficult.
- Sell the intake and buy a CPE Xcel intake. This intake will keeps your MAF calibrated to stock specs.
Since the engine is tuned so conservatively from the factory, your engine probably isn't at any real risk- yet. It will be if you add on other modifications that continue leaning out the fuel mixture, though- a high-compression, high-boost car needs accurate fuel metering. If you do keep the intake, remember to keep checking future CEL's with a scan tool- you'll never know if it's a too lean code or something much more serious.
Anyway, it sucks that Mazdaspeed has released yet another intake that throws CELs. I tried warning some guys in that other thread but got a lot of flack for it. All I wanted was for owners to check their fuel trims.
[quote author=Mazdaspeed33 link=topic=71302.msg1253331#msg1253331 date=1173242882]
ohh and i did clear the code came back with in 1 hour
[/quote]What will mazda do about the cell cause by their own CAI ? I would think they will have a problem with hundreds of people bringing their car in for cel's caused by a genuine Mazdaspeed part.
well stretch I guess I owe you an apology, but you didn't have any evidence until after you made the comments. I hope this is an isolated incedent because there is no way a dealer is going to be able to fix this. I wonder if mazda will make a re-flash for the ecu if the problem occurs with a bunch of cai's. Do you have any other mods.
[quote author=Mattleegee link=topic=71302.msg1253487#msg1253487 date=1173248458]
Maybe take off the BOV also
If you take off the BOV, reset the ecu and find the CEL still comes on, then you know for sure it's the CAI (assuming that's your only other mod, of course).
If there's no CEL, then you know the BOV is causing it (in conjunction with your CAI being installed).
With all this electronic crap they put into cars these days, BOVs have been known to play with the airflow when you don't want it to. Not saying it is now, but it's certainly something I'd look into if I were diagnosing the problem.
MS CAI's are bad now?
holy jumping to conclusions batman. wait up for robbin and get a little more info before we blanket statement things ehh?
this is akin to the false problems in the issues section. People dont do enough research, they saw a few things on tv and overnight became an expert.
Im not saying you are wrong, but you hardly have evidence to book a case at this point.
this is directed at post #2 if someone is having problems following along.
A forum community dedicated to Mazda 3 and all Mazda vehicle owners and enthusiasts. Come join the discussion about MazdaSpeed performance, modifications, classifieds, troubleshooting, maintenance, and more!