Lean @ WOT

Discussion of tuning specific to MAZDASPEED3/MAZDASPEED Axela/Mazda 3 MPS vehicles
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Lean @ WOT

Post by mituc »

To be honest I've never seen a 2.3DISI-T primary O2 sensor going bad like this, but I've seen this with aftermarket sensor with a different response curve, with inappropriate aftermarket MAF sensors, and with exhaust leaks.
However, I can't rule out the possibility that the O2 sensor is clogged or has a weak wire which does crazy stuff when the car accelerates hard.

On the other hand I wonder what adding 12% more to your current MAF cal will do. Maybe it is that much larger, maybe the internal diameter doesn't help the MAF register the amount of air it should if there is no air straightener in there. With custom stuff you can easily end up in such situations...
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Dolfius
Posts: 64
Joined: May 31st, 2017, 2:54 am

Re: Lean @ WOT

Post by Dolfius »

Okay so update time - the screamer pipe on my setup was angled in such a way that the exhaust stream flowed over the secondary o2 sensor, where it's supposed to read the clean oxygen I imagine. This caused it to report incorrect readings to the ECU.

The moment I directed the screamer away from the sensor, voila! Problem solved.
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