Yesterday I decided to pull out my scanner and check my LT fuel trims with the donaldson. I noticed that they were in the 15-19% with the IAT sensor reading 105 degrees. From what I understand if they go over 25% they will throw a code. The car has had over 1000km to compensate for the extra air but I would still get a code say every 300km. Yesterday I took my stock factory 2002 airbox and cut the top and sides off it( looks like Doug Rippies piece) and installed a fram CA3914 air filter. Drove for about 100km cruising, racing stop and go and checked LT fuel trims again. They were now in 6-7% range and the IAT sensor was reading only 75 degrees. Now I could not feel any seat of the pants difference between the two. Is the donaldson flowing so mauch air that my computer cannot compensate? I will be taking the 2 setups to track this weekend weather permitting to test-I also just got my cold air box for the donaldson to test as well. I don't have any dyno numbers as I feel the track is the best way to see what performs better.