Exhaust vibration issues after fitting a cat

[loves2spooge]

Hi everyone.

I've not had my S14 long and I had to get an MOT the other week. It failed on emissions because it had no cat...I had no idea...probably something I should have checked. Anyway, I put a cat on and it passed just fine...now I know most of you probably use a De-Cat pipe for regular use and then re-fit the cat when the MOT is due but I kinda want to leave it on. I'm by no means an eco-mentalist or anything but after removing it I haven't really noticed a loss in power so I don't feel the need to remove it. Except for the fact that the cat is now making contact with the floor and at speed it is creating awful vibrations...I have to slow down for ****s sake! This is not acceptable!

My mechanic who passed it told me that while fitting the cat I have shifted the exhaust system closer to the body which is causing the vibrations. I tried to move it back but it's not having any of it. I have noticed that there is what looks like a mounting bracket on the exhaust next to the cat, with a corresponding bracket attached to the floor....they look like they should be linked somehow which; if they were, would make it easier to shift the exhaust away from the current point of vibration (I hope this makes sense).

What I need is a decent image of the entire underside of the car so I can see how they are linked. I know most of you will tell me just to de-cat it but I'd like to try and make the cat work if I can. I've tried google images for days and can't find the info I need. If anyone understands the brackets I am describing I'd really appreciate an image of them.

[sambarnzee91]

It is this kind of bracket you on about?


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[sideways14a]

The stock cat becomes a fairly serious restriction once you are pushing decent power, at around 200hp you wont notice a massive increase but there will be a noticeable spool up difference.
If your runn a bar of boost with a map and other mods then not noticing a difference with the cat in would likely point to other problems as its very noticeable.

You could bend some brackets but my old s14a always used to hang low when it went in with the big kitty on it for mot day... then one day i melted the innards of the thing and that was that.

[loves2spooge]

It is this kind of bracket you on about?


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Hey thanks for the pic but no..this bracket is after the cat. Both the brackets have two holes that look like something is meant to be screwed into them. I think I'll try to bodge something to attach the to each other...something adjustable so I can move the exhaust over. It's hard to explain...probably should have got some pics while I was under there.

[sideways14a]

Why dont you just refit the decat?

[loves2spooge]

Why dont you just refit the decat?

I may well do...as I said...I'm no ecomentalist but I use it everyday so I kinda do feel bad about pumping crazy levels of CO2 out.

[sideways14a]

Really?
The amount will be insignificant.

Tell you what, you keep the cat to save some co2 and i will set fire to some tires each week. If you do refit the dekitty i will just keep setting fire to students instead which put out far less noxious gasses (unless they are ginger)
That way your saving the world with the decat.

Sideways mafs is olways rite

[Chriscooke]

I hate the cat in these cars, really chokes the car and it revs really lazily when fitted, saying that if you want to keep it you could possibly tweak the hangers or use jubilee clips to help pull the exhaust to where you want it

[Actual_Ben_Taylor]

You probably have the wrong size cat, there are 2 different versions - 350mm for the S14A and 315mm for the S14.

Bracket goes to the gearbox mount:



The whole thing looks a bit like this:

[Jonny Wilkinson]

IIRC the mounting brackets have a rubberised section, do they not Ben ? Does yours, loves2spooge ?

Maybe post some picture of what you have by way of brackets and someone will be able to suggest a fix.

[loves2spooge]

IIRC the mounting brackets have a rubberised section, do they not Ben ? Does yours, loves2spooge ?

Maybe post some picture of what you have by way of brackets and someone will be able to suggest a fix.

This is what I should have done in the first place. I'll get some this weekend.

Thanks for your help everyone.

[Actual_Ben_Taylor]

IIRC the mounting brackets have a rubberised section, do they not Ben ? Does yours, loves2spooge ?

Yep, you can see it in the pics above, between the 2 metal sections (directly above 'ou' in remove m'ou'nting bracket).

I still think it has the shorter cat fitted...

[jdm_virgin]

if you need the bracket i think I have the one attached to the cat that was on my S15 and should fit. I will look when i get home

edit: is yours a 14 or 14a? as may not fit the 14

[loves2spooge]

You probably have the wrong size cat, there are 2 different versions - 350mm for the S14A and 315mm for the S14.

Bracket goes to the gearbox mount:



The whole thing looks a bit like this:

This is definitely the part. I have everything from the bolts in the middle to the rubberised bracket still attached to the car but nothing on the left (if that makes sense). I manages to make a bracket myself for the time being that has completely fixed the issue...for now. Thanks so much for all of this...I love this site, you guys are so helpful.

[loves2spooge]

Thanks Guys...fixed for now with a home made bracket. It's an s14a and I did get a 350mm cat for it. Hopefully the bodge will hold until I can get the original part.