Evo newbie here! I have experience in ve-based and aftermarket ecus but stock ecu evo is giving me some hard time.

I will post datalogs and tune later but here is some info before that.

2006 EDM ix, stock rom, stock turbo, stock injectors (recently serviced and flow tested at 624cc/min). Only modifications are 3" exhaust, decat, 3" downpipe, greddy dry flow cone filter and walbro 255 pump. Pump gas, no e85.

My problem is that the car runs overly rich through out the load ranges. At cruise I'm getting lambda 1 (using wideband) with LTFT -12.5% and STFT ~0%. Idle is at lambda 1 but forgot the trims, log to come later.

As soon as I start to accelerate and the car goes to open loop I'm getting lambda 0.71-0.63, pig rich. This is verified with two different wideband sensors and black smoke from the exhaust.

Before I got the car it was tuned by well known tuner in my area but no one remembers what intake did it had back then. Exhaust was already installed at that point. The tuner likes to tune these to ~0.8 lambda st wot and that's something I was expecting to see myself.

I've compared the stock rom tune and my tune and haven't found anything odd. My current tune has identical injector scaling and maf scaling compared to stock rom. Most differences are in mivec table, fuel table (my current is leaner than stock) and ignition table so tune shouldn't explain the difference.

Externally I've ruled out boost leaks (tested with smoke and pressure, no the diverter valve is not leaking and yes the throttle body seals are replaced), timing is spot on and I'm not getting knock count either.

At this point my only idea is that it was tuned on stock intake/filter and my current filter throws off the maf characteristics. If that's the case how should I go about correcting it since all loads are affected? Injector scaling would be the easiest since it's single value that affects all areas?

I'll post log and tune files later today,
Thanks in advance