View Full Version : N249 bypass Leon Cupra
Hi All ive been looking at the treads on how to fit an N249 bypass all looks pretty easy just a bit confused on what i have to do with the resistors? and he pipe that is conected to the Fpr and inlet manifold goes directly into the back of the engine bay so is it still ok to blank that off? i take it that that pipe is what im bypassing??
Depends on what model of engine you have but the bypass removes the vacuum chamber that sits on top of the rocker cover and the connector is either on it or down the front of the engine under neath the metal plate by the dipstick. You need to put a resistor in this connector so to keep your ecu happy. Block off all pipes going to chamber then you then basically run a new vacuum hose from the outlet on the bottom to the manifold to your dv with a t-peice in between going to your fpr.
Thanks for the post i have a 1.8t leon cupra i think its under the inlet mani some where? have u done this small mod? did it make a difference?
Yes I have removed the lot and it gives a much better dv response as it removes ecu interference. You should have two outlets on the right side of the inlet manifold. One should be going to the fpr so remove this and replace the pipe with some 4mm inside diameter vacuum hose all the way to the dv. Cut it in half and install a t peice and run that to the fpr. Just block of the vaccum chamber by taking the pipe off and putting a bolt in the end. If yours is the same as mine the actual n249 valve (along with the n112 valve which controls the seconadary air injection system) is attached to the underside of the black metal plate that sits in front of the dipstick, this is what controls the vacuum chamber but with that bypassed it cant do anything. You only need a resistor installed into the n249 if you have actually removed the valve but it can be done by just bypassing the chamber like i said above.
Soz i don't explain these things too well, but their is loads of threads on here for it.
Lol!!! dont worry it was very usefull, thanks Natalie.