Ok, so I'm back again. tried putting a cold air intake on my 2004 Mazda 6I with a 4cyl. I left the air intake temp sensor plugged in, pulled battery cable off to reset computer and let car learn it. I have loss of power, rough idle and feel a stumble driving down highway. With the intake on, it shows two codes, cyl two misfire, and o2 sensor stuck lean. Anyone know whats going on? have no trouble with car with factory air box setup on it.

 

Did you plug the vaccuum line by the white ball! (1st pic)
And leave the green solenoid plugged in! (2nd pic)
of course you'll have to disconnect battery again.
Double check for other vac leaks, tightness.
If that fails, might be a good idea to clean MAF, and throttle body.

 

Sounds exactly like the EGR is sticking open due to the EGR vacuum dump hose being plugged off from an air box delete. If so, yours would be the 400,000 th one I have seen. Don't plug the vacuum hoses off.

 

Sorry bud, your wrong, you need to cap off the one by white check valve as i stated.
As per K&N instructions:
(2.3L models only) Remove the vacuum elbow hose from the one-way valve as shown. (Fig. 9)
11. (2.3L models only) Insert the M5 pan head screw into the end of the vacuum elbow hose. (Fig.10)

Here is the pdf instruction sheet:

http://www.knfilters.com/instructions/57-0615_inst.pdf

 

I don't see your diagram but since when does K&N know more about every Mazda ever made than the factory? Look up EGR vacuum dump. Plug that hose and it holds the EGR open. PERIOD!!!!

 

So I have done everything as instructed, still has fluctuating idle and less throttle response and power. Not sure what I should look at or try next.

 

On my car that vac line goes straight to intake plenum, however, I personally am not familiar with his vehicle, but it's worth a try as he is getting lean mixture. Diagrams are the attachments.

 

What is everything.
after re-hooking up battery, let idle for 5-10 minutes. Now re-learning has begun, adjusting. Take it easy for the next 30 miles. Hopefully cel code not lighting anymore at this point.

Are you sure it's a cold air intake and not a short ram intake?
Pics would be nice.
What brand name is the intake. Is the MAF sensor on a straight or beside a bend.