Hey everyone. New to this forum and have an issue. Have an 04 6I with an auto trans. Recently installed a cold air intake onto my ride and it starts nice, but has rough/fluctuating idle as well as loss of power under any acceleration until about 4000rpm. Is there anything in particular that I would have to change to smooth it all out again? the only other mod (so to speak) is I have removed the stock mufflers and replaced them with 3 1/2 stainless steel tips for a throaty sound.

 

Put the factory intake back in & see what happens.

What did you do with the VARIABLE AIR DUCT (VAD) CONTROL SOLENOID VALVE on the factory air box base?

 

Did you disconnect the battery so the ecu can re-learn the new set-up?
The VAD solenoid needs to be remain plugged in. Circled in pic.
also the vac line where the circular white thing is in pic needs to be plugged (just above rad hose).
I would also clean the throttle body and the MAF (with battery disconnected).
When was the last time you changed the PCV valve? Mazda never changed it! Again battery needs to be disconnected for this change.

 

I plugged off the check valve, but not right at the check valve, capped it by where it goes into factory air box. I did not disconnect the battery however, I will surely do that along with plugging off the check valve at the check valve and see how it reacts then. Thanks for the help.

 

The hose you capped going to the factory air box is the EGR vent. If capped it will hold the EGR valve open creating a huge vacuum leak. Just leave it hanging and it will be fine.

 

Thanks for the help and ideas. I'll definitely try them when I have the time to play with it again. Right now I have multiple trouble codes for the evap system with the factory setup on the car. Anyone else have this trouble? and what fixed the issue? it says I have a leak in the evap system and o2 sensor is lean at idle. I've checked all vacuum lines and the canister purge solenoid, still no luck.

 

Have you tried clearing the codes?

 

The reason for the small hose going to the air cleaner box (the one you capped) is that the egr is pulled open by vacuum,the vacuum must be released when it is commanded closed so in the event of an EGR valve failure the exhaust gases coming through that vent hose can be run through the engine and not into the atmosphere. Capping that hose will simply hold the EGR valve open as it can't close due to the hose being capped. It's an EPA thing.

 

ok, so I did exactly what u guys told me to do, capping off where the check valve is, disconnecting battery, leaving vad solenoid plugged in. after everything, the car started and died about 5 times, then when I started it again it had a fluctuating idle and easing into the throttle it had a miss. is the setup different from a 4 to a 6 cyl? I do have a bad purge solenoid, which im replacing tomorrow night.

 

I have a mazda 6 i2008 I also put in a cold air intake and getting a ruff idle and my check engine came on idk if it’s hooked up 100% but I’m sure it is my stock airbox just had the breather tube that’s all but my cold air intake has one thin tube and the thick on for the breather I have been spending countless days trying to figure this out lol