Page 1 of 1
Decat and remap E53 (2004) 3.0d sport
Posted: Thu Mar 05, 2020 6:33 pm
by Edward R-W
Hi all,
Has anyone taken out the catalytic converter on the 3.0d? I'm looking at ideas to improve performance on my E53 but I'm not looking at spending huge amounts or upgrading to a V8 petrol model. A remap looks like the best option for money vs gains, I didn't know whether to couple this with a decat and there are any issues with engine management if this is removed, with exhausts in mind I was also looking at fitting less restrictive muffler back boxes also. I wouldn't be looking for more noise just something a little more free flowing.
Re: Decat and remap E53 (2004) 3.0d sport
Posted: Thu Mar 05, 2020 6:49 pm
by StuBeeDoo
Not specific to the E53, but my E46 330d was (allegedly, he had no documentary proof) remapped for the previous owner. The swirl flaps were definitely blanked by the time I bought it.
I deleted the EGR and the cat. The cat delete was a stainless pipe from a firm in Glasgow, but I can't remember the name now.
That car was not only quick when you wanted it to be, but over the course of 50+k miles it averaged 40+mpg and it never got anywhere near failing the MOT on emissions.
Re: Decat and remap E53 (2004) 3.0d sport
Posted: Thu Mar 05, 2020 7:28 pm
by X5Sport
Re: Decat and remap E53 (2004) 3.0d sport
Posted: Thu Mar 05, 2020 8:43 pm
by neil50
Checks on de-cats and DPF have got more vigorous.
I know people sometimes rip the internals out to leave the cat and DPF itself so it doesn't look any different, but I have also heard stories of MOT tapping the cat / DPF with a screwdriver to see if they sound hollow and then reacting accordingly if they believe it has been tampered with.
Re: Decat and remap E53 (2004) 3.0d sport
Posted: Thu Mar 05, 2020 11:06 pm
by Edward R-W
I would keep the original system and place it back on the car for the mot test and any new system would be a stealth version meaning it would be hidden out of sight from the rear of the car behind the bumper so it wouldn't draw attention.
The 'legal' stuff doesn't bother me, even remapping your car voids your insurance unless declared.
I'm more interested to know if anyone has done a decat and had any problems, can it be done easily, does it affect the engine management/lumpy running etc, does it churn out more soot from the exhaust, does it pass an mot with no cat etc . . . ?