When I bought my car from the dealership, it was advertised as a 2009 VW Jetta, rather than an APR Stage 2 GLI. Good for me until I moved to California and am going through the headache of getting it smogged. As I was not the one to tune the car, I don't have an OEM downpipe to swap out the apr. This 02 sensor spacer (after reflashing to stage 1) worked exactly as I hoped. I had installed it prior to having the car reflashed, and the 02 and CAT sensors were ready by the time I got home. This saved me from having to purchase a stock intake and downpipe. Build quality is excellent, and for a part I had to purchase, it looks pretty nice too. I'm not too sure why other people were complaining about the install, although to be fair I only installed one on the rear 02 sensor, and I have a little baby CAT, so I had it in less than 15 minutes, including the time it took to jack up the car. 10/10 would recommend