mk2 1.8 exhaust , cat & egr

[Ebod]

Hi all, I've had a bash at searching for 10mins but not stumbled upon anything that helps me out at my limited skill level.

I've got a stock mk2 1.8 exhaust and to my knowledge the egr is still there.

> Can EGR be easily be switched / blanked off without causing MOT issues and engine check lights? Can someone talk me through it?

> The carbon can thingy alongside the intake. Is it a replaceable consumable or can it be cleaned/reused? How'd ya know whether its knackered or not?

> I see forum posts about de-catting and understand at a basic level its removing an emissions gadget that gives a slight improvement in power. Similar to egr valve, is this done at the risk of MOT/legality problems?

> Finally, more for vanity than noise, I would like to end up with a twin pipe back box on my 5. Coupled with the fact I'm prepared to remove cat/egr ( if MOTs allow ), can someone talk me through what options exist and for example doe choice of backbox affect upstream bits?

.....seems I'm paying the price of driving dull diesel saloons for 25yrs that I am so out of touch with petrol cars. Last ones I messed with actually had dizzy caps and points!

[Lazza]

Hi Ebod

On an otherwise standard car, there is no benefit from removing the EGR.

The carbon canister just helps to absorb fuel fumes from the fuel tank to stop them venting to the atmosphere. They don’t get blocked or dirty. Again, no real benefit from removal on an otherwise standard car other than being a bit smellier. I had removed mine but I put it back on.

The exhaust catalyser helps to reduce the O2 emissions from the exhaust. They do add a slight restriction to the system so there is a small performance benefit from removal but it is small, probably too small to make a real world difference. The main reason people do it is to get a noisier exhaust. If you remove it on a Mk2 you will have to refit for mot each year as it won’t pass a test without it (unless you have a VERY friendly mot guy).

A twin exit exhaust makes no more noise than a single exit exhaust. People (me included) fit them for the looks. The exhaust system is that, a system. You can replace the different parts but unless they are well matched and are designed for your setup, you will not get a performance improvement. What you will get is more noise. If you get it right it will sound great on acceleration but still be comfortable on the motorway. Get it wrong and it will just be loud and with an annoying drone on the motorway.

I know it sounds like I’m being negative but I’m not trying to be. I’m being realistic. If you saw my car you would understand that I really am not anti-mod on these cars. You just need to do a lot of homework on what mods you really need. Start by deciding what it is you really want from your mods. Is it performance or just a better sound?

[Mazda Mender]

To gain anything you need to set up the breathing and the exits as a whole full sysyem no point in just making her bteath better if she cannot let it all out smoother and quicker but you wil get miniemal benifit , unless it is about extra power? Or just a look.
The best thing you can do is service her correct..make sure the braking system is spot on..alignment and good tyres
..suspension is a personal choice and will help..

Extra power is a total different subject...
M-m

[Ebod]

Thanks Lazza & M-m, Unless there is a noticeable benefit then I'm more than happy to leave the EGR & carbon canister thingy well alone. I don't get it why some people get excited about empty engine bays and have no problem with pipes/wires/hoses if they are doing a job.

Re the cat topic, I absolutely don't want any 'excessive' noise and MOT legality issues. So the middle section of the exhaust is staying put. I have a K/N typhoon intake and know its pure asthetics, but that makes a bit of a gruff noise then stamping on the gas.

The twin exit issue stems from the fact I've just collected a rear bumper from Menders Mansion which has been cut for twin pipes. Hence I wanted to alternate to twin to compliment the bumper once its ready to fit.
I've seen one on an ebay breaker , but its miles away and no way to assess its condition to justify the £130 asking price. Also not sure a Mk2.5 1.6 device will bolt up to a mk2 1.8?

...so conclusion is I'm on the hunt for a nice twin box...but don't know what a fair price is...any if there are specific types to aim for......or avoid.
Cheers

[Lazza]

Mk2 exhaust is different from Mk2.5.

[Mazda Mender]

Mk2 exhaust is different from Mk2.5.

Back box is the same..

Personally i like the uniform of the twin at the back £130 is ok for a s/hand s/steel unit..does that include P&P ?..
And you cannot beat a bit of noise to know you are having fun..
Fit one buddy...i'll show you a induction kit to get that will not break that bocket and give more smiles per miles..
More power is a different topic...
M-m