Just a quick question - fitted my catch can yesterday to my S3 and didn't fit a 1 way check valve into the brake servo line. car runs really rich, huntsto start with then revs up to 2000 rpm and stays there with loud sucking noises from the tip, is in limp mode, backfires all the time and when you get below 2000 rpm ish it starts hunting and then pressing the throttle does nothing. you have to turn the car off and on again to get throttle response back
vcds shows throttle actuator 2 sensor fault and something about a throttle alignment fault sorry to be so vague. anyway, took my throttle body out, cleaned it and put it back in, still the same - performed the realignment on vcds and it just shows error.
tried a different throttle body and got the same results. smoke tested the system and smoke was pouring out the catch can system, so tightened everything up and that illiminated that (the leak) but it still runs as already explained. have another throttle body on the way to me as we weren't completely sure the one we used to test it (out of a leonn cupra r) was working correctly either because the engine has died!
however my question is, sorry if this sounds retarded, could not having a check valve in the brake servo (or something else i may have missed when doing the catch can - i have gone back through all the instructions numerous times thinking what i could have missed or not put back in etc and the brake servo check valve is the only thing i can think of ) cause the car to run like this and throw up those fault codes as its over compensating for something?? or is it complete coincidence that the throttle body dying has caused all this and that the catch can system is ok?? my engine is a BAM by the way. Josh