Unfortunately the first post on the forums would be about something not pleasant.
First off - car is a 2001 Skoda Octavia 4x4 with the ARX engine, hence the K03s turbo and the full SAI, n112 and n249 package.
Ever since I got the car I had issues with the cold start but not other issues. Then being very smart I got a tune which resulted in a cut at around 3,000 rpm - the car just stops accelerating followed by a big bang somewhere at the front and then I have to get off the throttle and back on it and everything is fine past 3,500 rpm.
After changing coils and sparks, knowing that the stock DVs are prone to failure after a tune, I got a new DV. Being the smart lad that I am, I ended up getting the infamous SPLITR from Forge. The result was... The exact same behavior. After vising another tuner, he concluded that the issue was with the SPLITR and indeed, disconnecting the vacuum going to it, putting a small screw to block the vaccum line. Indeed the issue with the cold start and the cutout was gone. However, I knew that running the car like this was not fine, and I was mildly worried that with the disconnected DV I still couldn't hear the distinct tutututu, which I should be getting at this config.
I ended up bypassing the N112 and the N249 (the correct way - getting the vacuum from the manifold, not tapping into the FPR) and the result was a much better DV operation, however by twisting the SPLITR I was only moving the cut out point between 3 and 5k RPM. Disconnecting it again made the car run perfectly.
A couple of days ago my 007P arrived, since after reading many posts about the beauty that the SPLITR, and having the tuner opinion that it should not be used on a 1.8T, I decided this was my point of failure. After I installed the 007P (tried both ways) I get the same result. Engine rattles like a mofo when starting up and cuts off a 3k RPM. Whatsmore, with the vacuum line disconnected and the much clearer noises that the 007P does compared to the SPLITR, now I can certainly say that when disconnected I can hear air going trough the filter (running a standard cone filter which results in a woosh sound). However, when connected I can hear only a sound of air going trough a small metal pipe (thats what it sounds like) below 3k RPM and can hear the air filter woosh above 4k. With the 007p disconnected, I cant hear any sound of turbo surge, which I guess I should get.