does any one have the part number for the n249 valve?

N249 - 078 906 283 A

cheers martin. i changed one valve yesterday and found a split pipe aswell but i didnt change the valve that is held in with 2 philips screws i take it this is the n249 then.

Not sure tbh as i have never changed one but i'm sure someone on here knows.

Two phillips screws? Sounds like the boost pressure sensor to me, where abouts you looking? What car is it on?

Don't remember any screws when replacing the N249.

its on a vrs 52 plate im looking under the plate at front of engine there is 2 valves there one held in by rubber mount the other by 2 screws. i changed the 1 with rubber mount car still hesitating on boost and running the same as before i changed it. so wondering if n249 is the one at end near the throttle.

Yeah you are right, are you sure its not the DV?

Yeah the one held in with the rubber mounts is the N249

I'm going to try one of these for the 17705 fault

im running a bailey dump valve before the throttle body dv seams fine inside but car is not pulling well and dump valve pressure sound does not blow off very loud anymore.

wot is the other valve next to the n249 and wot doe that do?

im running a bailey dump valve before the throttle body dv seams fine inside but car is not pulling well and dump valve pressure sound does not blow off very loud anymore.

wot is the other valve next to the n249 and wot doe that do?

That's the N112 (Secondary air injection valve), which actuates the secondary air injection combination valve (allowing the secondary air pump to blow fresh air down the exhaust).

It uses the vacuum system to open the combination valve, so that's why it's there. I wouldn't bother replacing it, as I can't see how it would cause your symptoms. But if you do try it, let us know if it does anything!!

Sounds like you've done the N249 (with the rubber mounting). After I changed mine, it fixed my sudden boost loss when pulling away problem. But I still have the 17705 code, but with no bad side effects....

New N75 and intercooler to intake hose next.......