So it seems my N75 blew and I've been scourging the net trying to get more info but ended up rather confused.

So by now I know what this valve does, however, there's so many versions of it that I don't know which is which. From what I've read I'm not necessarily interested in the upgraded versions, I just want to replace the stock but I don't know what letter after N75 is for the stock? OR, if it is truly worth it to upgrade when your car is pretty much stock (mine is stock + borla)?

Also, does anyone know of a good place to buy one online? ECS has a cheap one but it seems to be their own version of the N75 (http://www.ecstuning.com/Audi-B5_A4-...ctrical/ES122/) anyone had any experience with this one? It's cheaper than the rest so it caught my eye.

Lastly, I read that the N75 is commonly mis-diagnosed, if so, what else can I check before I blame this sucker?

Your input is greatly appreciated!

By the way, I have a CEL, running VAG reveals the following DTC:
17956
Boost Pressure Regulation Valve - Open Circuit
P1548

 

theres a guy on here that sells all this stuff i forget his name but he has a blue a4 with a big *** turbo on it look for him and talk to him

 

I think the ecs looks pretty cool. but if youre going for stock then i guess it wouldn't interest you. But if you could pick up more boost then why not?
I guess it would be important to hear reviews tho cuz i dont know the quality of the part.
I'm sure you could check the audi dealership for the part, or just the number

 

i think they stopped making the n75?X? that came with the car and i believe the stock replacement is the n75F. But you can call the dealer to confirm that. Upgraded versions will put you into limp mode if you have a stock tune. The Race valve in the link could cause problems for your car.

Since it is a $100 part I would be sure that it is your problem before buying a new one. If the electronic compnents fail, then you should get a fault code. what are you symptoms?

 

I've got the ECS version on my car now, i think its just a "h" version of a stock unit.
The one I removed from my car was a "c" version thats what came on my car new as far as i know(98.5)

I cant tell much of a difference. sometimes I think the race one does boost higher as advertised, but my POS car cant tell much difference between the two.

Why do you think your valve is faulty?

 

Is he the one who represents AHM Motorsports or something of the sort? If so I know who he is. Thanks for the tip

 

I would be definitely interested in picking up more boost if it was as simple as swapping a little valve, but as it is our cars, it is never like that. From what I've read unless you're chipped or have upped your turbocharger, swapping the N75 for the high-performance ones is mainly asking for trouble... Limp modes, shortening the life of the stock turbo and all that fun stuff.

I replaced my turbo less than a year ago (stupid me didn't know at the time I could've gotten a K04) so I want to keep it running through it's natural life, hehe.

That's mainly why I'm interested in just the stock one. If someone has a different opinion/experience and recommends I upgrade, then by all means, I'm all ears (eyes)!

 

Thank you for the info on that race valve. Yes, I called the dealer this morning and they sell the N75 for about $80 which is reasonable as far as what I've seen online.

My symptoms:
My car feels severely underpowered (though I haven't checked how much I am actually boosting) and I got a CEL. Hooking it up to Vag gives the following DTC:

17956
Boost Pressure Regulation Valve Open Circuit.
P1548

I've read that one can rule out a few things before blaming the N75 and having to replace it, do you know about this?

 

Are you running stock configuration/parts on your car?

I believe it is my valve because I have a CEL that gives me the P1548 code (Boost pressure regulation valve - open circuit) however, I want to check everything else before I go ahead and spend almost $100, if you have any suggestions as to what else to check I'm all ears.

Thank you.

 

I would go ahead and check the wiring and hoses that go to it before replacing it.
does that code throw a CEL?
there are people that bypass their n75 for a MBC but leave the wires plugged in and i dont *think* they have problems with it throwing codes... but i dunno. The way I understand it is that it sends a signal to the n75, but there is only two wires so there is no way for it to measure anything it does, it just a valve. Therefore it wouldnt be able to tell its bad. Now that I think about it I guess maybe if its totally fried it then it could give you a code for an open circuit, cuz that would be just like unplugging it?

try searching around some more for that code number:
17956
Boost Pressure Regulation Valve Open Circuit.
P1548

and see if you can find some more info on what can cause that just to be sure