Decat Fitting

[clarky]

How difficult is it to fit a decat on an NA MR2?

The pipes Ive seen look as though they bolt on and off? Is this the case and if so is it just as simple to swap the cat back in at MOT time?

thanks in advance

Clarky

[Bibbs]

I think the NA is easy (well, compared to the tubby).

Should just be a pipe with a flange <fnar> at each end.

Just make sure you have loads of spare bolts. Could be worth getting some zinc coated ones so when you need to swap back, the bolts are not all rusted solid ;)

[clarky]

Nice one - MOT due in sept - then I think its time to make more noise!

[Bibbs]

Nice one - MOT due in sept - then I think its time to make more noise!

NA's seem to 'bark' more after a de-cat .. I didn't get much more peak volume, I did get more response and mid range noise.

On a turbo, you get quicker spool and can hear the turbo spooling noise more pronounced through the exhaust.

[clarky]

Well with the custom 4" twin exit it barks a fair bit as it is - but you cant have too much!

[zebidi]

bibbs, is it safe to fit my decat pipe without changing any of the ecus settings? i have a rev3 turbo.

the turbos run rich anyway right?

[Bibbs]

With an NA you may have an O2 sensor in the cat .. this will need to put into the de-cat (with a spacer so it's not in direct airflow, and a restrictor -plate with a hole- so it doesn't get the full airflow -if there is one) as without you'll probably ECL.

Turbo's - a de-cat is a good mod. Because mine was pre June '95 (when a cat is needed) I just got a garage to take a power drill and crowbar to my cat. Left the pipe and drilled out the middle.

[zebidi]

With an NA you may have an O2 sensor in the cat .. this will need to put into the de-cat (with a spacer so it's not in direct airflow, and a restrictor -plate with a hole- so it doesn't get the full airflow -if there is one) as without you'll probably ECL.

Turbo's - a de-cat is a good mod. Because mine was pre June '95 (when a cat is needed) I just got a garage to take a power drill and crowbar to my cat. Left the pipe and drilled out the middle.

so the car ran fine without any settings changed? i read in a mag this month that a supra blew up because of the decat pipe adding too much more boost.

[Bibbs]

Yeah, the supra used the cats as a boost limiter (bottle neck), when you take the cats out, the boost doubles.

The MR2 isn't quite as bad.

If you get the sensors sorted, it's fine.

[Mr Wabbit]

Hello, I just through i would let you know. I fitted a de-cat to my 1999 N/A the other day and it was a right pain in the ***** lol. I managed to get 3 of the 4 bolts which hold the cat in place off, only to find the last blot was rusted, ended up having to cut the dam bolt off :D other then thats its a very simple job. undo the 4 bolts holding the cat, remove another 2 holding the exhaust in place (to give you better access to the cat) then its just a job of putting the de-cat in place and putting new bolts back on. All in all if this 4th bolt had come off like the rest i think its about 1hrs job tops. (just pray ur bolts arnt rusted)

Oh yer there isnt no sensor that goes on the cat so there is nothing to worry about. its just simply take cat of put de-cat on.

Lee

[clarky]

Thats what I like to hear .. thanks mate!

[MR2vince]

also depending on the cars year its exsempt from emisions testing on your MOT, so you shouldnt have to swap back to your CAT for testing

My car a 1990 so doesnt get tested.

Ive just bought a decat and will be fitting it to my N/A when i exchange the flexi section sometime this weekend

vince

[clarky]

Nice one - feel free to take some pics!

[Steve-O 2006]

Its possible that your car will pass the emissions test even without the cat... apparantly the Cat only makes Half a % (0.5%) difference in emissions when this website tested one. Also a garage near me tested a Scooby with a cat and then decatted it and re tested it and their was hardly any difference.

[zebidi]

Its possible that your car will pass the emissions test even without the cat... apparantly the Cat only makes Half a % (0.5%) difference in emissions when this website tested one. Also a garage near me tested a Scooby with a cat and then decatted it and re tested it and their was hardly any difference.

it all depends on how healthy the car and what petrol you use. i was told a while back that a healthy engine would p!ss an emissions test. thats why i change my oil every 5k miles religously.

that and i like to keep it running sweet.

[Steve-O 2006]

just had the Cat wipped off my 190E and the car is now VERY Loud and feels like it has more power!!! :D...

My 190E (Give it 2 years and a MR2 will be sitting their ;) ) :) -

[davidathomas42]

I had my De-cat fitted yesterday

I have a L'reg Rev 2 N/A MR2 and i bought the de-cat off eBay, took it to a friendly kwik fit to get it fitted, they had to take out four bolts, giggle the thing about a bit to get it loose, then put the new pipe in and fasten it in with the 4 new bolts i got with the pipe, easy as that,,, no o2 sensor and no ubiking around

they charged me the handsome fee of going to the local chippy and picking up some chip butties for the lads.

cant say it gets any easyier than that.....

[Steve-O 2006]

I had my De-cat fitted yesterday

I have a L'reg Rev 2 N/A MR2 and i bought the de-cat off ebay, took it to a friendly kwik fit to get it fitted, they had to take out four bolts, giggle the thing about a bit to get it loose, then put the new pipe in and fasten it in with the 4 new bolts i got with the pipe, easy as that,,, no o2 sensor and no ubiking around

they charged me the handsome fee of going to the local chippy and picking up some chip butties for the lads.

cant say it gets any easyier than that.....

Did you notice the difference in exhaust tone / loudness on the MR2?

[zebidi]

Did you notice the difference in exhaust tone / loudness on the MR2?

i'd think that it would, even my yaris sounded way loud with a decat, it sounded EVIL with the nur spec i had

and even MORE evil with no back box lol

[davidathomas42]

my mate said it sounds a little louder or powerfull but too be fair i could not notice, been on the M1 today in it and it gets up to top speed much easyer now!!!! plus better in mid range power, not massive but defenetly an improvement. noy sure if the speedo is acurate, but i was doing 145mph with ease today, getting my k&n induction kit on thursday so will update how that goes later in the week.

[clarky]

Hmm ... want to do the missus's but Im worried about the noise levels now! We'll see - I guess if its too much I can always swap it back.

[Steve-O 2006]

Maybe my Merc is much louder now Because I have no silencers in it now... just the RAGE Stainless Steel backbox...

My Mercs exhaust Pops and bangs much louder now as well (Sounds like a gun going off or something when I change gear / let off the accelerator :) )

[zebidi]

my mate said it sounds a little louder or powerfull but too be fair i could not notice, been on the M1 today in it and it gets up to top speed much easyer now!!!! plus better in mid range power, not massive but defenetly an improvement. noy sure if the speedo is acurate, but i was doing 145mph with ease today, getting my k&n induction kit on thursday so will update how that goes later in the week.

blimey,imso surprisedno ones mentioned about the 145 on here, in the yaris bit i nearly got banned for mentioning left foot braking!

de-catting the yaris made 4th and 5th more fun, will tell you all about the mr2 de-cat when i get it back.

[Steve-O 2006]

in the yaris bit i nearly got banned for mentioning left foot braking!

Tried Left foot braking at 30mph once... wont be doing it again :P LOL

[zebidi]

in the yaris bit i nearly got banned for mentioning left foot braking!

Tried Left foot braking at 30mph once... wont be doing it again :P LOL

i can drift the yaris with left foot braking before i got the suspension put back to normal. braking while accelerating shifts the weight back to the fron which give you more grip on the front for cornering.

but, to oversteer in a ff i think you must understeer first, you understeer, then you put more pressure on the brake with your left foot, shifting all the weight to the front which makes you oversteer, then counter steer and plant down your foot for weight shift to the back and front wheels drag you out of it.

would never try it in the 2 though. death wish