Just started to use learning view. Stupidly I reset my ECU about five miles before this screenshot.

My Car: Stock 2007 WRX 2.5. Running either Tesco 99 or Vpower.

The problem: Major hesitation issues in warmer weather, has been running okay recently with the cold weather but has a couple of hesitations during a WOT pull.

The car had a new MAF a few weeks ago.

Heres the leasrning view, already starting to drop in negative A/F readings.

 

That afr isnt the full picture matey, generally as long as it is within 5% it is fine. It also only shows that the car has had to add or remove a shade of fuel which can be down to several things, one being injector latency.

To be honest, learning view is a good tool but more for an overview than specific troubleshooter.
Download romraider and log timing, mass air, afr etc and see if you can single out the instances where it happens.
Are you sure the ecu rom hasnt been altered?

 

Im guess it could of been altered in the past, rest of the car is 100% stock. Still has all the heat sheilds in place ect.

RomRaider is what i was using this morning, but decided to act up when i tried doing a log. I did catch a couple of logs at idle tho, and a/f doesn't look good to me. Ill try post one up.

 

Heres a screenshot from the little i managed to get from romraider.