Hondata

Building a car for SCCA STX prep out of a 2007 Civic Si, and already have my 2008 Mugen Si in the same trim (same header, HFC, 3" exhaust, just a short ram on the new car vs CAI on my Mugen) and I took my calibration and loaded it to the 2007 with a new Flashpro unit. My car stays around 12.8 @ WOT, with mild fluctuations across the RPM range. On the 2007 the car will dip rich and tip in then pull back to a very flat 14.2. I added up to 20% more fuel at high loads with the same AFR. We loaded a Hondata provided basemap and the same thing occurred. Today I loaded a stock map and still having the same issue. While I haven't pulled the plugs to verify it is that lean, it is a notable fall off when it goes from the tip-in of where it's supposed to be to when it hit 14.2...it feels lean and down on power.

I'm not ruling out something oddball like a sensor but prior to the header and Flashpro install the car ran very strong without hiccup. Plus the o2 seems to be reading fine.

I've attached my calibration and a log from my Mugen (which works fine) and the 2007 Si. It looks like something is commanding it to run that AFR, as even on the same tune the injector pulse width is lower on the 2007 once it goes lean.

I cant see the calibration now, but check if you are changing speed density tables when you are using the MAF instead of MAP

arraydude wrote: Thu Jul 12, 2018 7:20 am I cant see the calibration now, but check if you are changing speed density tables when you are using the MAF instead of MAP

Should be speed density but I'm not on my laptop right now. It works fine in my car but not on the new one.

Is the AFM still connected and in the intake?

Yes. Just called my friend to go verify its plugged in and in the intake still.

This probably has to do with the difference between the 2 intakes.

If you look at the AFM readings they are not the same.

Spunkster wrote: Thu Jul 12, 2018 4:48 pm This probably has to do with the difference between the 2 intakes.

If you look at the AFM readings they are not the same.

How would I fix it if that's the case? The car had the intake prior to the header/FP without issue.

My only other thought is maybe something happened to the o2 when having the car welded in and it's causing some weird shenanigans when it dips below a certain voltage.

This is related to the difference between the parts on the cars. It will just need additional tuning to correct this.

Turned out the o2 sensor had failed in an odd way. Took my o2 off my car and tried it and it worked fine. I've never seen a sensor fail like that.