De-Catting

Evening Guys,
Alot has been written on taking the CAT off the exhaust system, but has anyone had a non CAT go thru the MOT? I am going to take mine off at the weekend and am wondering if i need to keep the old CAT to put back on at MOT time? I have a 300td, 159k - high mileage - no smoking problems with it at the mo though.

Have mot'd quite a few 300tdi's with removed cats, it is NOT a requirement for diesel vehicles to have a cat fitted, the smoke emissions are still very low to enable a fast pass (one smoke test).

Thanks for the feed back Stig
Much obliged

Wrighters, The De-cat is on my list of things to help my poor old girl breathe a bit better - 97 300 auto 165k.

Just wondering, do you have a part No. for the replacement down pipe?

I hav'nt got it with me at the mo as i'm at work - have a look at www.famousfour.co.uk - got mine from there. Will try and find the part number when I get back, so long as the wife isn't hogging the computer!!

hi, ive just de-cated my disco mines a manual box but I think its the same pipe ESR2740 that has the flexi in it. I didnt fancy the riged pipe that they fit on the defender I think that no. is ESR2297 but its cheeper, Mine was £57 plus p&p from ISLAND 4X4 LTD. good luck. BENI

Just done my 300Tdi at the weekend, big difference in performance! Like mine your Disco's done a few miles and the cat's probably blocked up anyway. Fitted the deffender solid pipe £30 inc delivery from Craddocks.

would a j reg 91/92 have a cat on?

No idea, mine is an M plate. Take a look under neath at the down pipe from the engine. There'll be a wire braided flexible connection followed by a small silencer type looking box. If you have this then its got a CAT, if not then both won't be there, just a straight pipe. Blanking off the EGR system helps on MPG and Performance also..

I'm thinking about doing mine. Did you have any problems fitting the solid pipe without the flexi section in it? How easy were the manifold bolts to get out?

The 3 15mm Nots/studs where ok, just used a bit of WD40. The solid pipe was a bit of a problem at first... but got there. You need to jack up the front passager side body, by the body so as to let the diff drop. Slide the pipe in from the front with the bend laying over pointing towards the passanger wheel, there's enough clearance between the top of the diff to turn the exhaust upover to the exhaust outlet...

manifold bolts can be funny little creatures, plenty of a lube on them to soak, dont go strait out with them, unscrew them then apply a bit of lube then wind them back in a bit then back out a bit fiurther if yer get me. saves a pain in the rear if you go too rough with one and it snaps.

I have finally got round to taking the CAT off and fitting the new pipe - WOW - what a difference! It picks up so much quicker and feels like a new motor - I have also fitted a K&N filter in the air box and must admit that makes a difference too - I intend to keep the K&N in for normal road use, and change it for the paper filter when I go off roading in dry, dusty conditions.