I'm really trying to look into getting a BOV for my A4 1.8t 1999 quattro tiptronic. I have heard that the engine runs rich after the BOV install because the ECU expects the purged air, hence it adds more fuel to mix with the absent air. Does this mean that I NEED a diverter valve, or the GFB Stealth FX valve (hybrid,) or does it mean that my ECU needs programmed according to the amount of air that actually goes into the intake manifold, instead of the false amount that the ECU is expecting? Also, is there any other hybrid valves other than the GFB Stealth FX? Thank you.

 

im not a fan of the BOV but this is worth a read
http://images.google.com/imgres?imgu...%3Den%26sa%3DG