de cat k8 post 1992 true or false

V6 Technical/Performance Discussions
Post Reply
mrswany2009
Junior Member
Posts: 10
Joined: April 11th, 2010, 2:34 pm
antispam: No

de cat k8 post 1992 true or false

Post by mrswany2009 »

i have been informed from uk websites (mx3 sites) that the cat cant be removed on post 1992 mx3 sucessfully. this is on the 130bhp engine we suckers got in the uk.

is this true or false,

it was my understanding the cat could be reaplced resulting in more horses.

regards
wytbishop
Senior Member
Posts: 5554
Joined: August 25th, 2004, 2:01 am
Location: Edmonton, Alberta, Canada

Re: de cat k8 post 1992 true or false

Post by wytbishop »

On OBD2 cars the O2 sensors are placed pre and post cat to measure the change in levels and so without the cat the engine would not run properly. On OBD1 cars this is not the case. O2 sensors are in each header and only measure the absolute levels so the cat does not affect ECU data. Unless something is dramatically different in the UK MX-3 you should be able to remove the cat on cars before 96'.

Or maybe I'm a total moron...hard to say.
94' RS/GS/MS/CF Monster Turbo...coming soon.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
User avatar
Mike Wakeham
Regular Member
Posts: 35
Joined: March 10th, 2006, 7:05 pm
Location: Wales UK

Re: de cat k8 post 1992 true or false

Post by Mike Wakeham »

It's more to do with the law of the land than anything else.

In the UK, if your car was registered in 1992 onwards, it HAS to have a CAT fitted to pass emissions on the MOT.

If you're pre 1992, so that'll be J and early K registration cars, you can remove it without the Fuzz or VOSA stitching you up! :D

I do know, (from people on UK-MX3) that if you're running a KLZE you can get away with removing the CAT, but that's only on a ZE converted car.
My Toys:
Stock (for the moment) 1996 K8 MX-3 with CAI
1998 Suzuki GN 125cc (my learner bike!)
Soon Honda VFR 400 NC30(when I'm not a learner anymore!)
User avatar
mazdags94
Regular Member
Posts: 1083
Joined: August 6th, 2007, 9:54 pm
Location: Hamburg, NY USA

Re: de cat k8 post 1992 true or false

Post by mazdags94 »

Technically, we have to do the same thing here in NY. They want to see a catalytic converter as well. However, a buddy of mine passes the emissions test and inspection with flying colors using just a glass pack. If you want the flow, just get a high flow resonator, test pipe (that looks like a cat), or just get a high flow cat.

As bishop said, you can remove it without a problem, but if its because of inspection purposes, I'd say get one of the mentioned parts and say it's a high flow cat.

But I know nothing of the UK laws, so maybe this wouldn't work. Just a thought for you :shrug:
'94 MX3 GS (black)-- 2.5L DE w/ straight neck IM, SSAC Headers, KYB-GR2's, Intrax Springs, CM Stage I clutch, OBX STS, filled front & rear mounts, CAI- SOLD :(
Buyer Feedback: viewtopic.php?f=37&t=62426" onclick="window.open(this.href);return false;
viewtopic.php?f=37&t=69003" onclick="window.open(this.href);return false;
"Amatuers practice until they can get it right; professionals practice until they can't get it wrong"
User avatar
Daninski
Supporting Member
Posts: 7055
Joined: June 18th, 2007, 10:51 am
Location: Trenton ON.

Re: de cat k8 post 1992 true or false

Post by Daninski »

wytbishop wrote: Or maybe I'm a total moron...hard to say.
Hard to say indeed. :) ........(paybacks a bit*h)

You can either buy a high flow cat from someone like Magnaflow or simply hollow out your cat.
OBD1 cars have only one O2 sensor per side in North America but in the OBD2 (96-97-98) there one O2 sensor then below that one O2 sensor monitor. You can omit the lower two with no adverse effects. If Europee-in MX-3s have an O2 sensor after the cat then I have no clue.
2004 Subaru WRX Silver, stage 2, minty interior.
2002 Subaru WRX Blue, SOLD (best E test numbers I've ever seen)
94 MX-6. Sold
92 GS KLZE 5 Speed
96 GS 5 speed, KLZE, Sold
95 GS Minty Shape Sold
92 GS Sold
92 GS Parts Car scrapped.
Feedback viewtopic.php?f=37&t=66348" onclick="window.open(this.href);return false;
7477th member.

I know you believe that you understand what you think I said but I'm sure you realize that what you heard is not what I meant.
User avatar
RS_OBD'oh_2
Senior Member
Posts: 2400
Joined: April 9th, 2007, 1:26 pm
Location: Calgary, AB

Re: de cat k8 post 1992 true or false

Post by RS_OBD'oh_2 »

if there is an O2 after the cat, you can get around it with a sparkplug spacer plug. It's a trick to pull the sensor out of the exhaust stream. You'll find it on many aftermarked headers and a google search will have the info you need(if you even need it).
Sleeper6
Regular Member
Posts: 1523
Joined: March 8th, 2010, 7:21 pm
antispam: ~SPAM*SUX~
Location: Canandaigua, NY

Re: de cat k8 post 1992 true or false

Post by Sleeper6 »

Theres also the old school way of just hollowing out your cat... looks stock just abit more open is all
92 GS gold (driver) worklog> http://mx-3.com/phpBB3/viewtopic.php?f=46&t=73405" onclick="window.open(this.href);return false;
93 GS red (wrecked)
:D I modify my ride so I can drive around the stupid people :D
User avatar
Tollis
Regular Member
Posts: 108
Joined: March 25th, 2010, 5:32 pm
antispam: ~SPAM*SUX~
Location: Pembroke ON. Canada

Re: de cat k8 post 1992 true or false

Post by Tollis »

Yeah I've got a hollowed out cat on my stock exhaust. Sounds pretty cool actually. It won't pass an emmisions test though good thing o don't need them here :p
Cody
1993 GSZE SE
Post Reply

Return to “V6 Technical/Performance”