BXProject

Opinions.pros and cons
thanks to Mat I have just learnt that from Feb this year.
although a diesel only has to pass a smoke test ( as opposed to emissions)
if a cat was fitted at time of manufacture then one has to be on the car for the mot now.
up til now a diesel didnt need a cat to get a ticket.

So like petrols, I guess you have to put the cat back on for test day.

I can see that de catting a petrol inproves the performance but there is no reason to de cat a diesel as it makes no difference to the performance or fuel consumption.

I had heard you get better throttle response and less turbo lag by decatting a diesel.
my other thought is the costly cat will last longer if its in the shed for most of the year lol

mickey taker wrote:I had heard you get better throttle response and less turbo lag by decatting a diesel.
my other thought is the costly cat will last longer if its in the shed for most of the year lol

How do you fare though if Plod decides to stop you for any reason and decides to do a tour with his clipboard?

How much is the fine for the contravention of 'construction and use' regs?

You have more chance of having a black baby.
Only registered police vehicle inspectors are allowed to check your vehicle at the roadside. If anything is found by an ordinary Plod his evidence will not be accepted in court.

On 4 occasions in the past, I have been told by a pc they are going to check my vehicle. I have offered to lend them a tyre depth guage (they can check these) and asked to see their vehicle examiners badge.
All 4 times I was then told to "fuck right off.

My cat is 11 years old now and I only had it off once to weld the front pipe. It was about 2 months before I could be aresd putting it back. It made no apparent difference to normal driving with the exception that it seemed to use more fuel.

To decat a diesel, you cut the cat open, hack out all the guts, weld a sleeve in and put it back together. Done it on the Picasso. Looks like it's there, but isn't. Goes through MOTs fine, and I got £40 from a pikey for all the innards.

Doesn't bring any more power/grunt as such, but the turbo did seem to spool up a bit quicker so low speed driving was a bit smoother. Decatting petrol cars never seems to make a difference on the dyno, so don't expect more speed, just more whooshing from the turbo

Thats sounds a good option Kitch.
if only I had the skills to make a stealth decat cat.


e.g.r. blanking plate seems a good option
Off the top of your heads, does anyone know if a 05 plate 2.0 tdci zetec mondeo 6 speed has an electrical connection on the egr valve as I dont want any silly lights coming up on the dash?

dont want to take the engine cover off just to find it cant be done on my engine.

Yay found the egr valve

One thing worth doing. If you follow the tube from the EGR valve to the plenum chamber. (Runs left to right behing the cam cover and a bit down) With a bit of fiddling you can remove valve, tube and plenum chamber by removing a few bolts and disconnecting the rubber pipe from the right hand side of the plenum.
Left to right loking into the engine bay from the front.
You will find that the innards of all the bits are litterally full of shit (up to 1/2" thick in the plenum)
Give everything a good clean as best you can and stick it all back.
Now the improvement in engine breathing is most notable with performance to match for just a few hours simple work that anyone can do with a 1/2 decent tool kit.

O.k. egr plate and k&n fitted.
I have even found a decatted cat on ebay.
kitch I realize the guts have to be removed but what does the sleeve do ?
Is it to stop the exhaust gasses buffeting around in the empty cat kind of like an internal straight thru pipe ?

mickey taker wrote: Is it to stop the exhaust gasses buffeting around in the empty cat kind of like an internal straight thru pipe ?

Thats about the jist of it too. oh and you will probably have to have thr ECU tweaked as it will throw on the EML once decatted..

Debated having it done on the Zafira of doom, but got rid and got a non FAP C8 instead - no cat = lots of black shit out the zorst on overfueling/clogging

the egr plate put the eml light on or so I thought.
turns out I forgot to reconnect the vacuum hose ,

no lighty all righty