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Discussion Starter · #1 ·
Alrighty,

I have a quick question. I recently picked up a diesel ST and did some looking around sites and ordered a E-9289 K&N air filter (the one with the removable cap). After i ordered it i found out that many aftermarket air filters put the car into limp mode....

Unfortunately i couldnt cancel the order since they had already shipped it when i found out about the problem.

So before i send it back i figured i should ask, did anyone ever get it to work right with the diesel ST ????

thanks.... ;)
 

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Are you talking about a replacement filter element or a whole filter box replacement like the Group A type induction? A replacement filter shouldn't cause any running issues? Group A type filters have been known to cause problems on some cars but then not on many others? From experience what can be the problem is poor installation which causes unmetered air into the system which then triggers the errors. I've run lots of different sorts of filters on lots of cars & the only one I had issues with was an old K&N 57i kit on my old ST24 and that was down to me tightening up the jubilee clips too much & distorting the pipework this letting in air after the sensor & causing the running problems.
 

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The k&n you've bought shouldn't cause any issues whatsoever, and as above its most likely the fitting of a group a cone setup that people are referring to.

Just for reference I have the same filter fitted to my st, albeit the mk2.

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To clarify.....

Generally you can put what filter you like on a petrol ST...(within reason!!) and it shouldn't cause too many problems...

Diesels on the other hand....

They appear to be very hit and miss! They can be a bit tempermental to excessive airflow.. I looked into it deeply before putting one on mine! There is no real pattern and some may post to prove me wrong... as mentioned some could be down to incorrect fitment.. but I don't believe all are.

It would appear most diesels dont like the RS airbox.. some seem to run ok with the standard paper filter in though! (but why would you want to run an open airbox with a paper filter... it just doesn't look right!)

RS airbox with K&N mostly equals limp mode!

'most' run ok with a K&N in the standard airbox... a few don't but most are ok!

I bought my K&N thinking 'oh well if it doesnt work i'll just stick it on ebay' but its been in since mid jan i think and has ran perfectly... def more responsive!!

click the 'my thread' bit on my profile bit to the left here... theres a nice little mod that makes the filter visual without throwing the car into limp!!
 

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Are you talking about a replacement filter element or a whole filter box replacement like the Group A type induction? A replacement filter shouldn't cause any running issues? Group A type filters have been known to cause problems on some cars but then not on many others? From experience what can be the problem is poor installation which causes unmetered air into the system which then triggers the errors. I've run lots of different sorts of filters on lots of cars & the only one I had issues with was an old K&N 57i kit on my old ST24 and that was down to me tightening up the jubilee clips too much & distorting the pipework this letting in air after the sensor & causing the running problems.
He's def talking about a replacement element in the standard filter box Nick, (it's the same part no. as mine which is just an element) They DO cause running issues on some diesels.... I think maybe due to people leaving the end of the air box open (filter cap off)... I'm assuming it's down to excessive airflow over the MAF sensor... I may be wrong on that! But the petrol is certainly a lot friendlier to filter mods than the diesel!
 

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The k&n you've bought shouldn't cause any issues whatsoever, and as above its most likely the fitting of a group a cone setup that people are referring to.

Just for reference I have the same filter fitted to my st, albeit the mk2.

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No its Definately that filter people refer to as giving problems Steve,,,, was in two minds whether to try one myself! But mine has been good as gold (phew!) The diesels clearly a moody mistress!!
 

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Steve Mk3.5 MP/275
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Alrighty,

I have a quick question. I recently picked up a diesel ST and did some looking around sites and ordered a E-9289 K&N air filter (the one with the removable cap). After i ordered it i found out that many aftermarket air filters put the car into limp mode....

Unfortunately i couldnt cancel the order since they had already shipped it when i found out about the problem.

So before i send it back i figured i should ask, did anyone ever get it to work right with the diesel ST ????

thanks.... ;)
Have had K&N Filters on my Mk2 and now mountune V2 Filter on my Mk 3.5 had no problems but they have both been Petrol engines,

but as Gaz says he has had no trouble with his but some guys on here have, bit hit and miss I`m afraid.
 

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He's def talking about a replacement element in the standard filter box Nick, (it's the same part no. as mine which is just an element) They DO cause running issues on some diesels.... I think maybe due to people leaving the end of the air box open (filter cap off)... I'm assuming it's down to excessive airflow over the MAF sensor... I may be wrong on that! But the petrol is certainly a lot friendlier to filter mods than the diesel!
School day every day then as the saying goes! Admittedly I have never had a diesel so was just going on experience with 'proper' fuel ( :whistle: ) so I never thought diesel cars could be so choosy!

:thumbsup:
 

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Discussion Starter · #9 ·
alrighty...

thanks for the replies, the filter is a replacement element one like gaz said. I think i shall give it a try in my car and see what happens, im curioious now and i suppose it will give me something to do :D

I was thinking if it goes into limp mode i could always stick a bluefin remap on it (which is something i do intend to do eventually), and if that fails theres a performance car shop near me and i could see if they can do anything :D
 

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Discussion Starter · #13 ·
well i fitted the K&N and gave it a good runabout and thankfully so far all is good, no limp mode :D

I have to say i was rather underwhelmed by it with the filter cap off it just makes the engine sound a little deeper and thats it...... so i will probably stick the cap in, in a few days.

at the very least i dont have to bother with the air filter for a number of years now :D
 

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Great news mate! Must admit I was a happy boy when mine worked after reading up on other peoples problems!

When you say you're underwhelmed.. do you mean in just the noise or the way the car drives as well? I found mine was certainly more responsive with it, though didn't really have a lot more noise....that said though, for some reason, my airbox lid with the perspex window in does make a bit more noise..goodness knows why!
 

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Discussion Starter · #15 ·
I was feeling a bit underwhelmed because adding k&n filters to my previous cars provided dramatic noise results, like my last car was a MK H astra 1.8 petrol and adding the k&n gave it awesome noise when putting the boot down, The ST is just a little bit of a growl...

But dont get me wrong i have only had mine for just over a week now and i still find it scarey fast, but still fun. :D

I have seen the perspex window mod and thought it was pretty nice looking and something for the "to-do list" :D I even thought that red led's fitted to the inside of the box along with the windo would be even cooler looking :D
 

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I have a K&N filter in mine, has always ran perfect and when I tried replacing it a few weeks back with an identical model.... limp mode!

No idea why, exact same make and model. I am also running an RS airbox.
I put the old one back in and works fine....

I am thinking of replacing the airbox altogether with a Diesel intake (Like Pic) and also a Wide mouth snorkel for behind the grille.
Anyone any experience with that before I send myself down a rabbit hole? lol

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I have a K&N filter in mine, has always ran perfect and when I tried replacing it a few weeks back with an identical model.... limp mode!

No idea why, exact same make and model. I am also running an RS airbox.
I put the old one back in and works fine....

I am thinking of replacing the airbox altogether with a Diesel intake (Like Pic) and also a Wide mouth snorkel for behind the grille.
Anyone any experience with that before I send myself down a rabbit hole? lol
Has the car been remapped in the meantime? I ask, because since my post above where I said mine ran fine with the K&N I've had a remap and since that it doesn't like a K&N anymore! I tried a foam filter too, which was fine when driving normally - but as soon as you gave it the beans it went into limp mode!
 

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Has the car been remapped in the meantime? I ask, because since my post above where I said mine ran fine with the K&N I've had a remap and since that it doesn't like a K&N anymore! I tried a foam filter too, which was fine when driving normally - but as soon as you gave it the beans it went into limp mode!
It has been remapped. Hopefully the airfilter can't be hard set into the map or else im left with a filthy K&N filter lol

Is there any other good air filters that aren't temperamental :D
 
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