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Hi all,

I hope all is well.

Can someone please help me understand what boost pressure sensor does and how it works with the ecu?

I was under impression that it is used by the internal gauge sensor but don't think that is the case and believe it feeds back to the ecu so engine will run lean or rich

Also when unplugged engine light comes on

I am asking because the head of mine broke and I glue it back together but it keeps breaking . When unplugged engine light is on and when not unplugged car is extremely lean if no line is going to the sensor on idle( reading my narrow band o2 sensor )

They are £40 on eBay for second hand which seems a lot
brand new is £150 from dealer. what a rip off

Do you know anywhere that sells brand new ones ?

Part number is Bosch ps66-01 hitachi 8529
My car as you might know is rb25 r34 get.


Picture is

http://i8.ebayimg.com/06/i/000/af/eb...5.JPG?set_id=7
Edited by stranger12
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https://www.sau.com.au/forums/topic/459058-boost-pressure-sensor/
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There is no MAP sensor on R34s. Well, at least there is no (M)anifold (A)bsolute (P)ressure sensor that is used by the ECU as a primary load sensor.

There is a MAP sensor to drive the boost gauge on the dash. This is not connected to the ECU.

There is a boost sensor, which is not really any different to a MAP sensor, except that it is not connected to the inlet manifold, therefore cannot be called a MAP sensor. This sensor is known as the boost sensor and is connected to the crossover pipe. The ECU does use it for making some fuelling decisions and for overboost protection, and you are correct, it will chuck codes if it is unplugged.

well on mine no codes at all. but the engine is not running fine .

I had a look at this post (below) and the guys says it is map and swap it with Haltech 3-bar MAP . I don't want to pay £150 if I can replace it with a haltch sensor but some are saying it is boost sensor and some saying it is map.

I don't get any code but just engine light.

http://www.sau.com.au/forums/topic/389661-link-g4-plug-in-vs-vipec-v44-plug-in/page-5

yep mine is a standard ecu. so 100% that is a boost pressure sensor not map sensor ?

I have seen number of posts people saying they have unplugged them but certainly it does impact the running of the engine so how can you unplug it and get away with it ?

Pretty sure they are only used as overboost protection.

Scotty, I was 100% with you until recently. But I have had a few people tell me strenuously that it is also referenced for some transitional fuelling decisions. I haven't actually looked into it myself or checked with Matt. Might have to have a little dig around the Nistune forums.

I just disconnect the hose on the Stagea's I tune, but you are correct, once tuned it would make no difference as the fuel map is modified. On a stock car it may well be used for minor corrections, either way you need it there and plugged in on the Stagea to stop the code.

All this because the OP is too tight to buy a new sensor... Just get one from a wrecked M35 if you want one that's not brittle.

Not tight but too mich for little plastic sensor that cost 30 pound brand new for all other cars and 150 for mine !

What is m35?

I am happy to pay the premium of 150 but rather buy an upgrade or somethibg that is worth the money and not the same sensor just for me to take it out few month down the line when i upgrade

When you unplug the pipe and have the sensor plugged it, it makes the car run lean. On idle my o2 reading is 0.5ish and with the sensor plugged and pipe blocked it is reading 0.2 and sensor unplugged and blocked around 0.8

FFS buy another sensor. Are you in England? Maybe not too many used ones around - try what I said yonks ago and email Kudos Motorsports - it won't cost you anything to find out if they can supply.

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