hey everybody,
new to the forum and audi but was wondering if i could get some help. i recently bought an 2001 a6 2.7t and he said it has an upgraded ecu. there was a box in the trunk with the original ecu with part number Bosch 4B0-997-551-AA. The box has part # 4B0-997-551-DX which that one is supposed to be in the car now. I was wondering if this is an upgrade ECU or just a replacement bc the only difference is the DX at the end. also it is boosting around 17-18 psi and i was wondering if this is stock or upgraded bc it is tuned by audi racing, supposedly, and i wasn't sure. i'd appreciate any help

thanks matt

 

Hello, welcome to the 2.7T, I have the same car, love it.
Stock boost levels are around 10 psig, so if you're getting 17-18, then it's certianly upgraded/tuned/chipped, whatever you want to call it. Quick question, where did you get your readings? Do you have a boost gauge installed?