Hey guys, as mentioned in the title I'm having issues with my 1.8t (2001, AUM, completely standard engine). It'll sometimes run fine (as far as I'm aware anyway, it's had this issue since I got it) but it will sometimes run as if it's just not producing the power it normally does. However, the problem isn't awful (i.e. it's not dead slow, just below what is expected of it).
Having done numerous VCDS scans over the last couple of weeks I have these two recurring fault codes:
17963 - Charge Pressure: Maximum Limit Exceeded
P1555 - 35-10 - - - Intermittent
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-10 - - - Intermittent
One thing to note, is ever since having this car, between gear shifts it makes a rather nice hissing sound, not really like a proper dump valve noise but a hiss nonetheless, I thought this was normal for this type of car (being a turbo) but I've read a lot about how people insist it should be silent on A3s/S3s due to the recirculating valve.
The reason I really want these codes sorted is I'd like to take my car to one of the reputable tuners on here for a remap, but I want all faults resolved beforehand to get the best out of it.
Thank you in advance for all helpful replies!