| Author |
Message |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 978
Reg: 11-2005
|
Ive done a quick search but didn't find what I was after so Ill ask...
Now I'm having my headers back exhaust done in just over a week or so. The stock cats will be removed but Ive just recently been thinking will the Cat light stay on if both are removed & replaced with tube? What electrical components control this feature?
If the light does stay on are there ways to have the car stop displaying the light as it sensing an apparent problem?
Thanks Guys |
Rob Andreacchio
Moderator
Victoria
Supercharged VT Calais & 1991 JZZ30
Posts: 2263
Reg: 01-2005
|
the cat light wont come on...
AND
I have 2 cat housings with pipe welded in so it LOOKS like you have cats.. 2.5" ones..
yours for $20 each. they are in the parts for sale section. (not sure on postage to NZ though) |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 979
Reg: 11-2005
|
Oh good, I just didn't want an irritating red light on the dash constantly when nothing is wrong 
Yeah, Im not worried about the cat requirement rule as it doesn't apply here and when I was chatting with my muffler installer he was saying how if a law does come out in NZ requiring you to fit one, any vehicle that does not have one will not have to get one installed once its in effect - it will only apply to ones with them removed after the law comes in to place. |
Peter Nitschke
JunkFilterer
South Australia
GT4.0 V8
Posts: 6882
Reg: 11-2004
|
Mike, the sensor is to detect if the cat is overheating, as it usually means unburnt fuel is then burning inside the cat mildly destroying it's ability to function.
So without the sensor being refitted, the sensor will never get hot. |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 981
Reg: 11-2005
|
Right, I thought that was the story I just wanted to make sure...
Also I would think the muffler man would know, but I may as well ask - would you have the these sensors refitted back up into the exhaust tube replacing the cats or just disconnect them?
Hmm I suppose if the cats were removed the sensors would be redundant and should be removed? Yes? |
Brett Moloney
TryHard
Queensland
UZZ31
Posts: 371
Reg: 07-2005
|
I found that when my cats were removed it was just TOO LOUD and certainly drew a lot of attention. Also when some Hi flow cats were put back on there was a noticeable power difference (in the good way!) leading me to believe that there was not enough back pressure. |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 984
Reg: 11-2005
|
Hmmm, interesting Brett, I will put that into consideration.
The main reason I want my cats to be taken out is that I'm sure they are one of the sole causes for an irritating rattle under the the car.
Plus they would be years old and probably need replacing soon - so If I do take them out and feel disappointed thats its too loud I can always get some Hi-Flow cats refitted No problem! |
Peter Nitschke
JunkFilterer
South Australia
GT4.0 V8
Posts: 6884
Reg: 11-2004
|
Mike, I had a rattle which was actually the heat shield on the cat which had come a bit loose. I fixed it by squirting a bit of high temp silicone in between the cat and the shield.
The exhaust shop could probably weld it back properly. |
Matthew Sharpe
Goo Roo
North Island
JZZ31
Posts: 1962
Reg: 10-2005
|
I'd get rid of the cats. They aren't required under NZ law and as you say, yours are old and probably no longer very efficient, so might as well cut em out! |
Antony Borlase
TryHard
QLD
UZZ31 (V8 Limited)
Posts: 269
Reg: 07-2005
|
Mike, I would get some of the Magic cats put in.
The knocked the noise down a little and left me on 154 rwkw when installed with extractors.
Plus they can give you a warm feeling inside knowing your car is as 'clean' (emissions wise) as a modern car...(well it make me feel good!) |
Benny Gammelmark
Goo Roo
NSW
V8 UZZ31
Posts: 1796
Reg: 07-2005
|
Mike, it's quite common on a lot of cars that the heat shield gets loose when the cats get old.
It does sound awful but it's less than a half an hour job for any exhaust or maintenance shop with a welder.
It happened on my mum's Toyota Corolla. Got to Toyota service, drove in, drove out 30 mins. later, no charge. Brilliant. |
Matthew Sharpe
Goo Roo
North Island
JZZ31
Posts: 1965
Reg: 10-2005
|
The problem with cats is it the production of them creates nearly as much pollution as they solve over their typical operational life, so they kinda aren't worth the effort. |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 985
Reg: 11-2005
|
Is that right Matt? Whats the cause of this?
Is it something to do with the material the cats contain to filter the various exhaust chemicals? or just the byproducts from when they are being made? |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 987
Reg: 11-2005
|
I picked up the two Lukeys for the system today. I also booked the installation for Tuesday the 30th 8am.....
Mmmm, Beautiful!  |
Mike Bradberry
TryHard
Queensland
V8 Limited
Posts: 437
Reg: 07-2005
|
Such a shame they're going under the car where they are going to get all dirty. |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 989
Reg: 11-2005
|
HAHA, Ill just clean them when I clean the car, I do even with the stock mufflers. Bit of a habit I guess!
You must remember you will still see these mufflers as the rear bumper allows a small under section of the mufflers to be visible from the sides - Should look good in Stainless! Looking much forward to the installation. |
Darryn Dewar
DieHard
Gisborne
UZZ30 Soarer
Posts: 546
Reg: 09-2005
|
 Isn't that the second pair you've bought?? |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 990
Reg: 11-2005
|
Yeah Sure is, At least this time it will be going on the car. |
Matthew Sharpe
Goo Roo
North Island
JZZ31
Posts: 1971
Reg: 10-2005
|
Mike Beck wrote on Monday, January 22, 2007 - 03:36 pm:Is that right Matt? Whats the cause of this?
Is it something to do with the material the cats contain to filter the various exhaust chemicals? or just the byproducts from when they are being made?
Pretty much. Byproducts from mining the catalyst (Platinum, Rhodium or Palladium are all fairly wasteful things to mine) creating the support structures for the catalyst (requires a lot of heat for ceramics) etc. Also in order to get the catalytic process running properly the engine needs to be running richer than it could be, so the car will waste more fuel, and though emissions which are directly harmful to plant and animal life are reduced, greenhouse gasses and smog causing emissions are actually increased by the catalytic process.
I think they have become entrenched in car manufacturing by outdated rules adopted from the US during the '70's and '80's and really need to be looked at more closely. Fortunately in NZ we have no requirements for them, so why bother? |
Mike Beck
DieHard
Ellerslie
Soarer 4.0GT
Posts: 997
Reg: 11-2005
|
Yeah, thats the way I see it too Matt
I cant see my cats doing a good job these days... Im sure they are the original ones from 1991, covers look stock, and they sure look like they have been there for some time!
I can tell if I leave them in Ill think to my self why didn't I get rid of them when I had the chance?... so I want them out - At least Ill be able to inspect their condition to see if they are any good still
One thing thats on my mind regarding the exhaust is how loud it will be with just the rear 2.25" Centre/offset lukeys, stock tip refitted and with regular bent mild steel tube from the stock headers with no joiner pipes.... Hmmm! If it's too loud for daily usage I'll have to add some 2.25" Coby resonators in the middle of the system on each bank... Hopefully this will not be the case though...
After a few chats with Pen about his 2.5" Dual system which interestingly didn't drone or have an excessively loud sound, it will be interesting to see how the same setup goes with 2.25" tube, no cats and same muffler capacity and model just ID of 2.25" and centre/offset....
I might have to get a dB meter to see how it goes! |
Leon Wright
TryHard
WA
V8 UZZ31
Posts: 452
Reg: 08-2006
|
From the exhaust I spoke to, his thoughts were that the 1UZ just don't get that loud with a full system (short of running out the headers i guess) as that was one of the things he discussed with me, said a lot of young lads want really excessively loud systems and most likely be disappointed if that's want I wanted.
But in saying that, he also said that he's never fitted an exhaust that sounded bad on a soarer, reckons almost impossible to screw up  |
Benny Gammelmark
Goo Roo
NSW
V8 UZZ31
Posts: 1802
Reg: 07-2005
|
You CAN get them to drone though. Mine did before I got Neil's headers.
I run 2.25" Stainless tubes with crosspipe, racing cats and std. rear mufflers (only one set).
I get 80db at 4000 rpm. and it sounds sweet. |
Matthew Sharpe
Goo Roo
North Island
JZZ31
Posts: 1979
Reg: 10-2005
|
It won't be too loud with the stock tips, and the mild steel will soften the sound a little over stainless anyway.
Drone would probably be your only concern... I don't think you'll need the resonators, but that'd be the way to go if you do get some drone. |
Mike Beck
Goo Roo
Ellerslie
Soarer 4.0GT
Posts: 1001
Reg: 11-2005
|
Yeah, I think the stock tips make it a bit smaller at the end due to their size, so that would minimise sound.
Your also correct regarding mild steel vs stainless - another thing is the exhaust rubber mounts cant be too tight other wise to much vibration will go through the car so reasonably loose ones suit better.. ....from what Ive been told, plus its makes perfect sense
Hmmm hopefully no drones will crop up - Id say the lukeys will help reduce it as there was pretty much no drone on my Honda that had a lukey - however its much different (v8 vs I5) and Ill find out when its done. |
Mike Beck
Goo Roo
Ellerslie
Soarer 4.0GT
Posts: 1002
Reg: 11-2005
|
Oh & there is just one other thing....
How do you exactly loosen the 3 header to cat bolts off? Theres hardly any space to get my tools in there. Ive read its wise to spray them with a WD40 type spray but once thats done and left over night how exactly do you get tools in the tight space to do anything??
I ask as my muffler man recommended that I attempted to loosen up the 3 bolts on either flange as it will take a long time to get them off in the shop then doing the exhaust its self.
I did look around on the forum and archive link but didnt really find what I was after...
Any ideas would be most appreciated.
Oh wow 1002 posts now & 'Goo Roo' status...  |
Avin Luther
Goo Roo
vic
Soarer uzz31 Limited
Posts: 1192
Reg: 07-2005
|
I drove someones V8 soarer around for a bit without cats, (when i was in New Zealand), it sounded awful, much louder. on the Dyno it got exactly the same result as when it had hi flow 3inch cats. so there is no power difference.
headers, twin pipes 2.25
it will be much louder without the cats. this particular new zealander just put some cats back in and is happier driving the car now. |
Mike Beck
Goo Roo
Ellerslie
Soarer 4.0GT
Posts: 1005
Reg: 11-2005
|
Hmm, Since I had a free day today I unbolted the exhaust from the cats so it was just running from the cat in the garage....
Bloody hell it's loud! Sound very angry, love it!
Its simply fantastic to hear my soarer sounds like a wild v8 - not some whirring thing as standard... Looking much forward to getting the new tube and mufflers fitted!
I must say it's really easy to get the cat bolts undone but not sure about the header to cat bolts - Perhaps I should leave them in, save the hassle. Plus there seems to be a mixed reaction about the cats going out... 
What to do... |
Dan McColl
Goo Roo
Victoria
Active V8 and a Factory Manual xf.
Posts: 1803
Reg: 07-2005
|
Do what ever maker YOU happy. |
Mike Beck
Goo Roo
Ellerslie
Soarer 4.0GT
Posts: 1023
Reg: 11-2005
|
Yep, Will do Dan.
I think I might just flag it and leave the cats in there... See how it goes from there! Ill be just that happy to have consistent sized tube, 4 less mufflers, no 'Y' joiner pipes or a resonator!
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