Hi guys, I bought my vectra 2.0 tdi 2004 and was happy with my new car, within hours of my purchase I was a member of this great web site. Well the first thing I read was about the air box mod and this is what I did the next day of buying the car, I removed the bottom part of funnel and cut off a part of the top funnel, the tried to see if there was any difference and soon after I drove for about 10 minutes I noticed that she would not pick up over 3000 rpm also I noticed the emissions light came on, so I put the bottom part of the funnel back in the air box and she seemed ok after a short test drive but next morning starting off to work the flat spot was back, by now Iam thinking Ive bought a dodgy car hear from my local dealer and was even looking at my legal rights to take the car back as I spent all my money on buying the car and could not afford a costly repair bill. Well guys for about a month since I bought this car I've had this dreaded flat spot problem that it seems that most Vectra owners get at some stage, anyway I tried everything from changing the m,a,f sensor and a new air filter, cleaning the egr valve + the inlet manifold all of this and still the same, as soon as I got to 3000 rpm she lost power and my emissions light was on all the time this was going on, I was so F**K OFF with the car as I was not enjoying driving it at all,any way as I was tiding up my boot yesterday I found the piece of plastic that I cut off the top part of the air box, so I was Bord and thought to super glue this piece back to where it came from and it went on perfectly, started the car up all seemed ok waited till the better half came home from work and we went out for a test drive and WOW full TURBO POWER all the way for a long drive, it was great, next day NO emission light and the car it better than it should be, it seemed the small bit of plastic made a big difference to the car.
Well sorry for the long story but I know a lot of you guys have done this mod and I hope this could help some of you. Vectra 2.0 tdi what a great car