View Full Version : Removing the CAT??
I recently had a full stainless Steal zorst for my 2001 1.4s while the unit was being made i had him make up a CAT removal pipe,
car runs fine and sounds sweet etc.. But a few friends of mine are saying that removing the CAT on a new car like mine is bab as it will upset the ECU! somehting to do with the LAMBA sensor???:(
Can someone with a bit more knowledge than "One of my mates knows a guy that know another guy"
Put me straight on if removing the CAT is going to upset my car :confused: :confused: :confused:
Cheers guys
When my Lamda prob went up the spout the car over fuelled & stalled lots once warm
Not sure where it goes in (pre cat or after)
if Pre cat I can't see a problem
M
chriskaven
10-06-2002, 12:14
The Lambda sensor is normally located pre cat, or within the cat assembly. Some modern cars use (in addition to the normal lambda sensor) a CMS sensor (Catalyst monitoring sensor) which is located after the Cat or Cats. This works in the same way as a lambda sensor but effectivly moniters if the cat is working correctly. If it isnt it may flag a warning lamp or diagnostic flag.
If you can remove the Cat without removing the lambda sensor (ie lambda not part of Cat) there shouldn't be a problem, unless you have a CMS sensor. CMS sensors are always post cat.
So does anyone know if my 2001 Y plate if i have one of these CMS thingeys???
Bill your useualy the man of many tallents do you know?
Still a bit :confused: :confused: :confused:
Get under & have a look mate :)
ibizacupra
10-06-2002, 21:44
Originally posted by Miridor
So does anyone know if my 2001 Y plate if i have one of these CMS thingeys???
Bill your useualy the man of many tallents do you know?
Still a bit :confused: :confused: :confused:
Whats your engine code?
I'll look it up.
regards
bill
Any news on this yet? Considering custom build exhaust but have
no idea what to look for in respect of the cat + cms
Sorry i didn't reply yestarday.
Where abouts do i find the engine code is it on that plate at the front of the engine bay ??
Mark what you doing starting a car dealership;)
Did you go to Santa pod at the weekend??
If you didn't you didn't miss anything, rained all day didn't see any cars run and only 5-6 Seats!! Think i will wait till Trax, Anyone else going?:)
Originally posted by Miridor
Mark what you doing starting a car dealership;)
Did you go to Santa pod at the weekend??
If you didn't you didn't miss anything, rained all day didn't see any cars run and only 5-6 Seats!! Think i will wait till Trax, Anyone else going?:)
"Mark's World of tat cars"
Didn't goto the pod cos of the rain (and buying stock, sorry Polo's)
There's plenty going to Trax - so that should be cool
drop me an email @ work - I've lost yours
M
Did you know if you welded all the engines out of all of those cars you would have a fire breathing 4 litre 16 cylinder 24 valve drag car of a Seat:D :D :D :D
The quickest Seat Ibiza i ever did see running 13" rear wheels LOL ;) :p
I think the Engine in my Polo produces the same power - the S is a 75bhp one I think
so this 4 Litre 'beast' would only have 195bhp
I'll just have to drop a 1.8 16v in there instead now.
Gut the F***er & have some fun.
M
[just drop in a 1.8 16v is a relative term]
chriskaven
11-06-2002, 11:21
CMS sensor will look like a sensor sticking into the exhaust somewhere after the Cat. Dont know if your car has a Close coupled cat (directly after manifold) or Underbody Cat (under body!) or both!
ibizacupra
11-06-2002, 11:58
Originally posted by Miridor
Sorry i didn't reply yestarday.
Where abouts do i find the engine code is it on that plate at the front of the engine bay ??
Mark what you doing starting a car dealership;)
Did you go to Santa pod at the weekend??
If you didn't you didn't miss anything, rained all day didn't see any cars run and only 5-6 Seats!! Think i will wait till Trax, Anyone else going?:)
Usually stamped onto the head casting or block casting.
Should also be on your registration documents.
regards
bill
Nice one guys i'll have a look tonight and post back as soon as cheers guys:)
Hay Mark i could get you a 3.9 litre supercharge Range Rover v8 if you fancy it. Its currently sat on the workshop floor awaiting butchering into my Rangie, but you could have a crack with one of the many polos you got knocking about if you like:D
have taken the cat off mine and tbh doesn't make that much difference,it runs as normal as the lambda is before the cat but on the decat pipe theres a threaded hole that you could use to bolt in the probe,honestly don't think its worth the 80 od d quid i paid for it,wanna give it a wurl?have to put mine back on soon for MOT may even leave it off.
think it would help if i had a flowed head and cams etc but on a stnd engine not worth it not that restrictive.
and noisy:cheers:
just add to the above car is 145bhp over 130 stock with cat free exhaust and induction kit ,so there may be something in it:cheers:
chriskaven
11-06-2002, 20:45
About the threaded boss, I would be very careful about fitting the existing lambda sensor to a decat pipe. These sensors are very flow sensitive and are set up after much flow and rig testing to ensure they get a good representation of the exhaust composition. By moving the position just a small amount could cause non represenative signal back to ECU which could mess up the fueling!
If the lambda sensor is pre cat and not part of the Cat assembly you shouldn't have to touch the lambda anyway
Just found out that if you run a decat pipe your car is classed as "Not road worthy" i.e have a crash your not insured:eek: :eek:
Guess whats being taken of the car at the weekend:frown: Didn't notice any difference anyway so nothing gain nothing lost:)
Isn't insurance stupid :mad:
Cheers guys thanks for your time :cheers: