so i bought a ECU off fourtitude. its a stage 1 for the b5 s4 6 speed manual trans. i disconnected the battery, swaped them out, and when i start the car with the new ECU, first of all it idles about 100 rpm lower than it usually does with stock. and the ABS and traction control light is on. it seems that i have no abs when i break. and thirdly when i hit it in first gear, it kind of jerks back and forth.. is it my car, or the ecu?! the car drives fine when in stock.