Decatted Murcielago and Engine Management Light

[John Rutter]

Friends,

I am considering on installing a de-catted exhaust, for any of you have done the same how do I deal with the inevitable engine management warning light. Is there an ECU specialist who can mod the ECU's if that is what is required or is there a simple wiring modification.

Regards,

John

[Bunk]

I'm sure anyone who installs these can also do the ECU modification if necessary.

A bigger question is the noise. Have you heard one of these decatted? I had a 2003 Murci with a tubi exhaust and Larini sports cats and it was bloody loud. It sounded great at full chat but I used to be embarassed coming into my housing estate because the noise would just reverberate off walls and stuff and I felt like a bit of a twunt. I can't imagine what a decat is like.

[John Rutter]

Cheers Bunk, I guess I should have thought of that. I keep the neighbours sweet with alcohol and a ride out from time to time! I will take a recording of the car once it is sorted and upload.

Bunk said:

I'm sure anyone who installs these can also do the ECU modification if necessary.

A bigger question is the noise. Have you heard one of these decatted? I had a 2003 Murci with a tubi exhaust and Larini sports cats and it was bloody loud. It sounded great at full chat but I used to be embarassed coming into my housing estate because the noise would just reverberate off walls and stuff and I felt like a bit of a twunt. I can't imagine what a decat is like.

[sandysinclair]

Im currently running a tubi and 200 cell larini sports cats. I'd council that in that format it is just on the edge of too loud. It's 96db in the cabin under full acceleration and I'm going slowly deaf. But ....it makes the noise from the gods and to be honest after a few months I got used to it. I'd say a complete decat would be a step too far and you will have flat spot problems due to low back pressure and lower torque.I know a guy in Australia who has done this and the programming of the ecu took them ages..... My engine light is always on because of the back box and is normal. I'm on instagram under lambosand and have loads of vids on there if that will help?

[MDL111]

Going by how loud it seems to be according to the above - depending on where you are in the world, it might attract a little too much attention from the police. Read a few stories of people getting stopped in Germany and if the car seemed like it would not pass German TUV, then German cars immdediately towed to German TUV and foreign cars often had to be transported back out of Germany - driving prohibited

Just sth to consider as I thought about various modifications but spend too much time in Germany, no clue about other countries

[lambo_xx]

John Rutter said:

Friends,

I am considering on installing a de-catted exhaust, for any of you have done the same how do I deal with the inevitable engine management warning light. Is there an ECU specialist who can mod the ECU's if that is what is required or is there a simple wiring modification.

Regards,

John

Personally I wouldn't bother. If you are after more noise I'd get a new exhaust, quicksilver/tubi/larini etc. Decat with a "sports" exhaust is borderline ridiculous. I'm sure there was someone on here years ago had done it. I seem to recall it was 128db. As a reference point a jumbo jet taking off is 130....

[del mar]

Mine runs a Tubi Sport exhaust, but still has the cats and testing at Brands Hatch showed 113db.

A little above the 105db level they have...

[Davo456gt]

John, does Murci run Lamborghini LIE like the Diablo ?
if so, I think there is no chance you will get someone to modify the ECU.
In the Diablo, the CEL lights come on with the slightest problem.

Is it more power you are after ?
you may be better removing the front diff, and going to rear wheel drive only.

[Cerberaherts]

Blocking one of the pipes to the pulse sensors mounted just above the pulleys area stops the light coming on...

[John Rutter]

Hello Dave,

I'm told if I do not mess around with the Primary Cat's it should be OK. Super Veloce told me the light may come on after 20 mins or so then reset. I'll let you know how I get on. 633 HP is current figure and enough for me. Next time I see you I will explain

John

[lambo666]

I am assuming this is 'decatted' plus some sort of straight through exhaust.... I would certainly like to know, if you get your murci anywhere near this level....https://www.youtube.com/watch?v=go6kxyKSDZ0
what ever you decide to do, please do before and after videos if at all possible

[steveirl]

John Rutter said:

Hello Dave,

I'm told if I do not mess around with the Primary Cat's it should be OK. Super Veloce told me the light may come on after 20 mins or so then reset. I'll let you know how I get on. 633 HP is current figure and enough for me. Next time I see you I will explain

John

John, your car only has primary cats, as far as I know only US cars were fitted with secondaries!!
How loud do you want to go? My system is quicksilver, and retains the factory cats, and is quite a bit louder than stock. I will keep it that way but would consider larini cats if the originals ever need to be replaced. I have heard Bunks Murci, and it was louder than mine on open throttle.

[simonspider]

John I honestly would think twice about de-catting your Murcie.
Over the years I have tried virtually every different aftermarket exhaust going, including de-catting with each different one.
Whereas the Gallardo de-catted with a tubi back box and tips is probably the best sounding road car you will ever hear, the Murcielago with the same set up and de-catted sounds absolutely dreadful. More like a Morris Ital with a hole in the exhaust.I don't know why this is, perhaps an engine expert can explain.

I have found the best combo on the Murcielago is a tubi back box and tips for the loudness or a great compromise which you can live with every day is the tubi tips and retaining the (huge) factory back box.

Simon

[Davo456gt]

Simon, have you tried Kreissieg ?

http://kreissieg.ocnk.net/product-list/48

I'd love to get one of those for my Diablo, but they are a little pricey!

I would have thought replacing the back box, would have saved a lot of weight and improved acceleration - right ?

[simonspider]

That is one I haven't tried!
Huge weight saving with replacing the factory back box but it depends on your personal taste on the loudness of whatever combination you go for tips/back box wise.
I must be getting old as even just the Tubi back box and tips set up is a bit too loud when you use the Murcie every day

[del mar]

simonspider said:

That is one I haven't tried!
Huge weight saving with replacing the factory back box but it depends on your personal taste on the loudness of whatever combination you go for tips/back box wise.
I must be getting old as even just the Tubi back box and tips set up is a bit too loud when you use the Murcie every day

How do you get on with track days and noise regulations ?

Are you still governed by the same controls that would effect me?

[simonspider]

Forget track days with loud exhausts its almost impossible unless you're on a de-restricted day or Blyton Park where there are no noise limits.
I don't/won't be using the Murcie on the track from now on.

[lotusespritse]

Lots of people run decatted Murci's in the US with no ECU codes. They just run spacers for the secondary O2 sensors. It fakes out the sensors to thinking the exhaust is cleaner when it's really just getting a smaller sample of the exhaust.

[845ste]

I personally have a quicksilver and are not very happy (for me a problem is not X exaust).
my F355 with Tuby sounded much better, like a F1 !!
in each case the primary kats remained and db are acceptable.

without primary kats I believe that arrest you right away .... and back-fire at high rpm

https://www.youtube.com/watch?v=ZfwtPHbMfXA

Edited by 845ste on Tuesday 3rd January 09:17

Edited by 845ste on Tuesday 3rd January 09:29

[Yipper]

If one is getting a decat, it makes sense to go the whole hog and get it remapped for a bit more grunt and flames at the same time.