whats up dudes, so this weekend I installed a short ram air on my04 RX8 and let the computer reset over night since I know that the new fuel air mixture is going to cause the CEL to come on in all likelyhood. Well my CEL came on while driving-not suprising since i did put the new intake on but i expected it to shut off it hasnt. and on acceleration at around 5.5 6 k rpm I get a hesitation/stuttering almost like the engine is flooding for a split second. Could this be because I possibly got the MAF sensor dirty? Or should I let the computer figure it out. I just dont want to drive it with aftermarket intake and risk damge to the engine even though I have the warranty for another 60k miles (yeah its a really low mileage car for being an o4). Any input/suggestions would be awesome I obviously can go back to my stock intake but I want to know if its necessary.

 

same problem...i have K&N short ram intake and RB air duct...had the intake for a while so im sure thats not the problem...the thing causing the CEL to come out is the RB air duct because the disconnected VDAF...it somehow trows a CEL...when i put the stock VDAF back on , it goes away and idles/ accelerates fine....

i reset about 4 times last week since i put the RB duct on coz my car didnt want to idle...kept dying.....now its fine and CEL is gone...but i saw it pop out for 5 min last night then disappear .....hope it doesnt come out again.....all i can say is , try reset-ing it a couple of times...i just think the ECU just needs to learn the change

it might be a different situation but hope it helps....reset it a couple of times for the computer to learn & get use to it

 

First we need to know what intake you put on it.

Second we'll need to know what the code is. You can go to your local auto parts store and they should read it for free.

It sounds like your MAF readings are screwed up. That can happen with poorly made intakes or incorrect installation.

Do not push the car until you solve the problem. A good aftermarket intake should bolt right on with no resetting, learning, or codes. It should feel great and smooth right away. So something is wrong.

Inspect your MAF to make sure it's clean and doesn't have any oil on it. This can happen with a newly oiled air filter if it has too much. If it does clean if off with MAF sensor cleaner only.

2nd Inspect your installation to make sure you don't have any vacuum leaks. A common one is not plugging the vacuum line nipple underneath Upper Intake manifold. It's right above your ignition coils. If this is left open it will suck in unmetered air and cause your air fuel ratios to be off and that can cause much bigger problems.

Then check all your other vacuum lines to make sure everything is in place and nothing is loose, uncapped, or leaking.

 

The VFAD is vacuum actuated. If you don't cap the vacuum line I spoke about it will suck in unmetered air and throw off your AFRs. Definitely read the Racing Beat instructions on this.

 

yes i did cap my vacuum line....i normally do my research before i actually buy anything so i had everything prepared and done...nice try tho


edit : i have the racing beat instruction in my hands now (i nvr throw away the instructions& boxes just incase i need to return the stuff i bought) and i read it over again just to make sure ur statement . No they did not mention to cap the vacuum line...

 

A well designed intake will not generate a CEL unless the installer did it incorrectly.

I just skimmed through the RB Air Duct instructions and it doesn't mention it.
Only the RB Intake Box installation instructions mention capping the VFAD nipple.

Maybe they assumed you wouldn't use the air duct without their airbox (even though many do).
Here is the VFAD nipple that should be capped:

Since you're an '04, do you have an MT or AT?
The '04 AT RX8s didn't have a VFAD.

If the VFAD isn't your problem, then I would look at the screen you installed into the air box outlet.
Make sure the mesh isn't deformed since its used to straiten the airflow across the MAF sensor.
Knowing the CEL code would also be helpful too.

 

..only a bit left on the engine warranty, depending on original 1st sale date
..it's either the yrs or the mileage, whichever comes 1st
..you have none on the bumper to bumper warranty

 

nah i bought a warranty in april when i bought the car that covers the engien for the next 2 years or up to 100k

 

The car comes with a 8yr 100K warranty on the motor core. If you paid extra for that you got taken. Hopefully you mean the powertrain and not just the engine core.

Either way have you checked your vacuum lines and pulled the code?

 

I like how you let the ECU reset over night, you do realize its not like cooking a turkey, you have to be driving the car for it to re- learn. Did you disconnect the battery for some reason ?

 

The RB duct is not your problem. Think about it......

The short intake is your problem.

Possible instalation problem.

 

I agree. When intakes first started coming out for the 8, I bought the K&N short ram. It was garbage. Cel would come on and periodically my car would stall. So shortly after I discovered the REVi intake w/ ram air and no problems since. I think you honestly just dont have a well designed intake.*-And w/o the ram air duct, a short ram is a horrible idea grabbing lots of hot air under the hood. You are probably losing instead of gaining H.P. considering the stock is adequate enough.

 

does anybody want to buy a K&N short ram?

 

Maybe a dumb question to you guys but are you both using at least 1 mesh screen?

 

i had my short ram for 3 year..didnt throw a CEL since the first day

installed RB air duct , was the first time CEL came out of my car for 6 year..

had no complains for the hot air ....i wouldnt call it garbage because its been good to me all this while...no CEL there since 2006...my car is 2004 btw.....
but i got the RB air duct coz its well recommended for good air flow which is logical ....but it does throw a CEL until u resolve the issue....

LOL...cooking turkey

just gotta go to a local shop and get them to pull the code out ...then search& research from there

 

I am doubting the ram air is causing it but maybe that extra velosity is causing the air to swirl before the MAF which would cause issues.

 

Or your engine is used to hot air

 

The guy is saying it happens each time he removes the VFAD so that sounds like the problem.

I would pull down the RB Revi instructions and read up on properly removing the VFAD. I suspect you have left a step out that is causing you the problems.

 

I have an 04 also and put the intake on in 04 that was crap. I am not saying yours is the same model than mine but I assure you mine was crap. Also the Stock intakes are finely tuned so even if you think you have a good intake, I am thinking your not getting as much H.P. as stock. Which neither of us can prove without a dyno.

 

haha...most likely got used to hot air

i miss driving stock...drove my buddy's stock 8 with no mods...miss loving the stock whine of the engine instead of the WOT of the short ram....all good... HP gain or loss within 5 HP is not worth being dynoed ...

r u referring to OP or me ? i dont have the RB problem anymore....the OP is the one with the short ram issue...and yes i do agree with shaunv74 to remove and re-install

 

yeah thanks everyone , it def missed the unplugging the vacum tube from the nipple and capping it..--gg on my part i know. the CEL is still on but the car no longer has any stuttering or running problems I am going to take it to autozone and get it plugged in to get the code read before I reset the CEL. I do have a question bc the insturctions I got were sh8tty and came with the cap and a pic i missed but actually said nothing about capping the nipple or whay to do it. SO should I just zip tye the hose I unplugged out of the way or is there something I should be doing with it. If all else fails I will just re-install the stock intake. As for the mesh screan no. It goes K$N cone filter-tube-MAF in tube-connected to intake. And yeah without a dyno I cant know for sure what gains I got. It does seem noticeable but then again I could just be "wishfull"??!! and I love the magnified sound caused by the intake. I did check the install last night its completely sealed. Ill get MAF cleaner today while Im at auto zone . Any other suggestions/tips are welcome Im knew to the rotary--as for the warranty I bought it covers all internal and lubricated parts of the engine/transmission and electronics and it covers the intake system as well _( i called the warranty company yesterday and they said yes the intake system would be covered under my warranty)

 

If you cant reset the CEL. try putting at least one mesh screen in. Im confused as to how your able to run your intake without one. That screen is what helps keep the air uniform when it enters the MAF, without it, the air would be swirling as it enters,
RACING BEAT WROTE THIS
We determined early on that it would be necessary to incorporate at least one mesh intake screen in our intake system. Mazda originally planned to use just one screen, but during late testing they determined that they needed to add one additional screen to provide good idle stability. During development and testing of the our intake we determined that we needed only one screen because the REVi entrance into the MAF sensor was very "balanced" – that is air enters into the inlet air horn uniformly form all sides. In the stock air box, Mazda chose to cut away a portion of the air horn to get a longer tuned length. This compromised design caused the flow to "swirl" as it entered the bell and continued swirling as it passed the MAF sensor, resulting in an unacceptable variable output reading. Tests showed that the use of one mesh screen in the stock box reduced this "swirl" condition; the addition of a second screen eliminated this from occurring.

 

thanks Blue- I went and got CEL code read and both codes said fuel/air mixture too rich probable cause dirt MAF or hot MAF but im betting its the swirling your talking about and I will def try the screen- oh and its a 6sp MT

 

That's not from Swirl. That's from the uncapped nipple sucking in unmetered air. Won't hurt to clean your MAF but I would reset it and see if it still comes back after you have the opening capped.

 

reviving this old thread......ok so saturday I installed a revi intake on my car (just the intake no air duct) and I capped the vaccum line with a cap I got at autozone. I went for a 100 mile drive and the car was fine...no rough idling or nothing of that nature. When I cam back to my area however my CEL came on.

Any tips or suggestions ? Thanks!