Cat removal

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lightning

lightning

Well-Known Member
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High Peak
My local Land Rover lndy say it is worth removing the catalytic converter on my 2005 Defender TD5
They say it will perform better and the MPG will be slightly improved.

They replace the cat with a silencer box.

What are people's thoughts on this. Is it a worthwhile modification?
They also say l should blank off the EGR valve.

Is this a good thing to do? An internet search proved inconclusive. When l did it on my Transit Connect tdci it caused running problems.
 
I don't want more noise! I drive it all day every day (5,000 miles in five months) all local journeys.

One problem l have is the exhaust system is badly sooted up. Do l need to take it on a motorway drive once every month or so?
I rarely get up to much over 2,000 rpm in normal driving.

I never had this problem in my Transit Connect tdci, but l drove that a lot faster and went to Wales in it every few weeks (150 mile round trip on the motorway) so that's probably why.
 
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I replaced my cat (2003 td5) with a straight through pipe after the cat became blocked with soot. The result to my ears was too loud and very intrusive when driving oround town. I cut the cat open and removed its guts and TIG ed it back up, Much better now and has a lovely turbo whistle which I like the sound of. I have also blanked the EGR and removed the valve assembly, I would reccomend doing all of these but expect a moderate increase in MPG. My 110 CSW does high 20s MPG.
Some claim mid 30s MPG...:D
 
I fitted a stainless straight through exhaust, and it is not intrusive at all, cat, centre box all gone, removed that EGR rubbish, all I have is a rear box. Made the exhaust note deeper with a hint of burble and turbo whistle on idle that was all. Can't say if the MPG got better or worse really as it was remapped at the same time, after I just bought it, so I have no real idea what the MPG was before nut it does 23-25 MPG currently on mostly short sub 5 mile runs. Its a 2005 double cab.
 
Remove the egr. It's useless. Drives a bit better without, too.

I have an early td5, so it never had a cat.... It's not too loud, and I get close to 30s for mpg and drive it daily. I think the cat is too restrictive.
 
Well l had the "EGR bypass kit" fitted yesterday.

The garage presented me with a box of substantial looking parts that they had removed, including a large part with a butterfly valve and a poppet valve in it, and a metal pipe.

The Defender does not feel any different to drive. And there is still a lot of exhaust stink.

I'm going to replace the "depression control valve" which somebody on here advised could cause excessive crankcase fumes, and can fail.
It's only £25 so worth a try.

After that l am not sure what to try. A gas mask maybe.
 
Depends what you read.

The garage that removed it have been Land Rover specialists since 1955, and also do all my MOT's....and the Defender is due in April so let them fail it for a missing EGR system if they dare!
 
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An update.

Since fitting the EGR bypass kit, there has been a reduction in exhaust smell. Also there has been an improvement in low rev performance.

Before, if you changed into third going up hill at 20mph, the Defender would not pick up, and required a change back down to second.

Now, the turbo starts to kick in, and it pulls better.

This did not happen immediately, it has taken a couple of hundred miles after fitting the EGR bypass kit.

As other people have not reported these improvements, l wonder if my EGR system was defective. The exhaust was certainly badly sooted up. Maybe the CAT is blocked too.

I'm going to get the earlier TD5 non-CAT front pipe fitted.
 
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OK so the decat pipe was fitted and the noise levels are hardly any different, slightly deeper exhaust note but if they had fitted the decat pipe during a service and not told me, l would probably never have noticed.

The turbo does come in a bit quicker at low RPM and it feels smoother, but l think my CAT was choked up with soot.
 
I'll keep updating this as nobody is commenting.
Looks like it is worth removing the CAT.

Slightly better economy too.

About 20 miles extra from 10 gallons. So about 2mpg more.
 
The garage who removed the CAT does my MOT's

But the TD5 engine was so clean when it came out that it passed without a CAT. I've had it checked today and emissions are actually lower now, than with the CAT fitted.
 
law changed within the past couple of years though, if there was a cat fitted it needs to be there in order to pass the mot. Or at least "look" like its there ;)
 
vilguy said:
law changed within the past couple of years though, if there was a cat fitted it needs to be there in order to pass the mot. Or at least "look" like its there ;)
Click to expand...

last year ;)



Item 1: Presence of Catalysts and Particulate Filters on Diesel Powered
Vehicles
On 16 February 2014 Section 7.1 of the inspection manual will be amended to include a check for the
presence of catalysts and particulate filters on diesel powered vehicles. Any vehicle where a catalytic
converter or particulate filter is missing where one was fitted as standard will fail the test.
 
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