To decat or not to decat..,that is my question

The Oily Bits S1 Specific Topics
1

Hi all,

Is it worth fitting a decat pipe to my k series exige? What benefits / drawbacks will i experience?

Any other mark 1 owners in the Chichester or Haywards Heath areas?

Thanks

2

It’ll be louder, and it’ll rev quicker as there’s slightly less restriction. Theres a placebo effect of that too, and you’ll think it’s quite a bit quicker.

3

My car came with a decat fitted, I had to change it back over for the MOT and haven’t as yet swapped again. I haven’t noticed a significant change but some would of been present. The notable effect has been the car has come to idle when starting more happily since refitting the CAT. I had intended to revisit a rolling road (my car has an emerald ECU) as I decided I needed to review the mapping, I think it was tailored more aggressively for track work. It may be in my head but the car has felt more civilised since reverting, but I do think that’s my cars mapping not the norm.

4

Thanks for the replies, is it easy to do yourself with just a trolley jack?

5

yep - its just up under the rear tray, so a handful of M8 or M10 nuts from memory to release the under-tray. Its a simple swap, it bolts simply in line between the exhaust and silencer. I don’t think I jacked my car up even …

Its a very easy and inexpensive mod. I am going to refit mine, as I’m curious if the idle is in my head or simply because the car has been getting more use recently so may of just burnt off some aged petrol or similar hence the lumpiness initially. My car had barely been used - less than 200 miles in 18 months - when I brought it so think it may of been showing signs of being stored.

good luck.

6

Thanks 60

7

I had one fitted for a short while on my non-emerald car.It seemed to trigger a slight misfire just on 70-80mph. I persevered for a bit as I was told the ECU would soon “recognise” the decat pipe and adjust accordingly (That may have been completed bollocks). It never happened and as soo I took the decat pipe off, the misfire disappeared. Run perfectly ever since.

8

The CAT will have a smaller diameter pipe than the cat replacement pipe. Mine came without like 60’s, since added one, still won’t pass an MOT emissions test, but I’m working on that.

Surprisingly it didn’t make the car much quieter. Dead easy to change out though.