I thought you guys may find this interesting. See this thread at Civicx.com
Intake Manifold Porting



You see this piece above? I vaguely remember seeing this when I removed my throttle body. The guy in that link removed this piece and actually saw his fuel trims change and the car adding more fuel at higher rpms. I left it alone not fully understanding it's purpose. Interesting stuff. His injector duty cycle jumped up from 74 to 80 (6%). Seeing this, this would've been my next modification. Just sharing!

 

d'art did hack that piece off on his intake mani. he mentions it threw a cel aftwerwards, prob for the reasons of fuel trim as described above. I will link him to this thread

 

I wasn't monitoring my fuel trims before I ported my intake mani so I can't 100% say one way or the other. Car is definitely peppier since I ported the manifold and the throttle body. I have yet to do my EGR block-off. That is for sure coming though. I did a coolant bypass which probably also helps. And I did the ram air mod, removing the left fog light and running air directly onto the Weapon-R air filter/intake pipe. After all that, the car is running a little richer, about 14.0 AFR at idle v. 14.7 prior to. My mileage is also slightly worse which would correspond to a jump in duty cycle. The CEL I am pretty sure was due to overtightening of the intake manifold onto the head, or possibly one of the 4 or so vacuum hose attachments getting filled up with plastic shavings. Once I cleaned and properly torqued the intake manifold all the crazy blinkys went away...

I have kind of lost interest in the Fit. I need to get back into the garage, but being in Vegas with no AC out there, she will probably remain in her current state until September. Still a good daily. It was a bit demoralizing going with the BC Racing coilovers and how brutally rough they are to drive on the street. I have softened the rear shocks which helped immensely, but I am missing my Z06 real bad as of late. Anyhew, it's a long row to hoe, I need to strip the motor and get the block over to San Dimas that should motivate me more than anything. Cheers, and best regards to you all. -d'Art

 

Man, you have a Z06. I can't see anything motivating you to drive that Fit.

 

Oh...really? Didn't know that. Thanks for the heads up. Thinking perhaps it let so much air come through that his fuel trims went outside the +10 range, meaning it had to add that much more fuel. This is interesting if this is the case.
Ktuner should be able to compensate for this, if you you had it.

 

I *had* a C6Z. I totaled her on Christmas day 2017 and bought the fit the next February. Since I never got to track the Z, I track the fit lol. And I do have ktuner and it does some corrections.