Got a mind boggler for you tech types...
 

I have searched and searched and searched on this forum and picked the brain of everyone i know with a rotary, and even guys that prep them for race...

okay, so I have a 2005 RX8 MT 55xxx miles on motor and tranny.

Installed/ modifications: Greddy Exhaust, Catless midpipe, K&N short ram with custom intake duct for lower IATs, VFAD removed and capped.
Problems: about a week ago i was driving home and my engine quit when i was coasting down from speed. Popped it back into gear and let the clutch out to start it up again and then took it out of gear and coasted did the same thing. Got home cleaned MAF, throttle body, and air filter and took it around the block, same issue. Finally threw a code for system too lean, so replaced plugs, coils and wires, CEL went out, but I still have same issue.
I now have no codes, which is strange because i don't have a cat and i would always have a cel on for cat defiency, it is no longer there. another intersting thing is that it won't stall on the cold start profile, and i idle just fine, i can even idle in gear and it won't stall. It seems to only do it coming off throttle out of gear when i am moving. It will try to save itself and stumble and bumble around 500 rpm for a couple seconds, then it will just quit. It starts fine and I have no rough idle. I also have no power loss... I am all kinds of confused, and hope you can help, Looking forward to your responses,
Very respectfully, Kevin Eells

Your "custom" duct tied to your K&N is screwing up your fuel trims.

pictures of said duct plz
do you have the 1st version of the K&N? If so, that used to mess with the MAF as well.

MazdaManiac, thank you will block it off and take a test drive, as a note the duct has been in for about two weeks, and this is the first time it caused anything to happen.

And as you already knew sir you were correct.. is there any way that i can duct cooler air up into there that will not cause this problem?

omg, get rid of that duct.

check your MAF screen on that intake. It might have a hole in it or come loose so the air is too turbulant for the MAF.
Better suggestion: get rid of the K&N and that duct. Replace it with an AEM intake and you'll be all set. The AEM is one of the best cold air intakes out there.

hahah yeah i had the V2 short ram from K+N and i had those same problems. took the intake off as a last resort after checking everything else, problem was solved and has been ever since. and that was last summer

I used to have an aem cai on my car. It really did make a little difference and I never had a problem with it.

is that a dryer hose?

oh god are you serious......


i think this would have been a better deal for you...
https://www.rx8club.com/showthread.p...ght=custom+cai