I honestly believe they need to do some checking on what's going on with those M box cars like yours. That is disappointing to see that their can be such a varying performance from A box to M box with APR chips and the other brands don't have that kind of difference. Personally if I had an M box car and wasn't stage III like r1eater, I wouldn't get an APR chip just because of what you've seen and my own personal experience with M box cars and their chips.
I'm just glad your happy with the chip you have and it runs good. Honestly, I want all the S4s on this forum to run good...regardless of chip. That way when they get into a street battle or go to the strip, they can represent what the car truely is capable of. Nothing I hate worst than running bad and getting beat. I can accept defeat when my car is running right, but not when it's running suspect. There's a black FRC C5 in the area that I sooo want a rematch with becasue my car was running like shit when I ran him. Put it this way...when I went to the strip, the car ran a 13.9s and 14.0s....when it should have been around 13.1s. Long story on what was wrong, but it was someone else's fault and not my own.
Have fun, be safe and kick ass on the streets. ;-)
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Rob aka "The 4DR Assassin"
Captain of the S4 Rowing Team
00 S4 Silver/Silver
93 Corrado SLC
90 Beretta GTZ
Audi S4: It speaks softly, but carries a big stick!

"You must be fast...cuz I was haulin' a$$ when I passed you!" 
"BUT do not look down on B5 as they will bite you in the ass with vengeance" by Oggie_s