De-cat

[jaykaybi]

I'm by no means a mechanic, so could anybody here advise on something I read recently -


I'm looking to de-cat my elise, which is apparently a very easy procedure (undo bolts, remove cat, do up bolts).

However I hear that the change in emissions can make the ECU throw a wobbly?
And also that the reduction in back pressure will mean a loss of low down torque?

Much obliged as always!

[Hollywood Wheels]

Is that a 111S you have J? If so I believe a de-cat is a no-no. Don't ask me why, I'm too stoopid to understand the mechanics!

If it hasn't got the VVC engine then a de-cat is a very easy job, and makes the car way way better sounding. It won't mess up the ECU because you have an S1, which doesn't have an engine management light, so jobs a good 'un. It probably will fail an MOT, but you can either square the garage away by giving them 20 notes to do the change before the test, or just do it yourself a few days beforehand.

E-Bay have got good used de-cat pipes for a tenner. It's just a straight hollow section of pipe so nothing to go wrong....

[jaykaybi]

Thanks Hollywod, it's a straightforward standard s1, so cheers for the nod.

Anybody able to shed some light on my second question, about the loss of torque caused by the reduction in back pressure?

Once again, much obliged!

[DSS123]

J,

As Hollywood says, The 111s is supposed to suffer from fitment of a CRP. The VVC mech likes a bit of back pressure aparently.

However the difference is completely undetectable and more than made up for by the sound. I have a CRP on my 111s and if feels and sounds way better than when I fit the cat back on for MOT.

Standard engine should be fine, bit of a ball ache come MOT time, but well worth it because combined with a decent zorst and induction kit, makes the elise sound like it should do - i.e. not a metro.


Dunc

[jaykaybi]

Big thanks Dunc, and a lovely car you got there!