Catalytic Converters

[alien]

Ok, after an extensive search and even a trip to both the vitara and sierra bibles - i came up completely empty handed - although i now know alot about zook eggs and the space time continuum!

I'm running extractors and 2" pipe on the zuk, but the standard cat - i want to find a cat to replace it that is a 2" dia pipe from factory and will flow well...

Anyone managed to find a matching cat on a wrecked car? Im thinking perhaps commodore/falcon ones might be 2" but not sure how they'd go.

Thoughts?

[Gwagensteve]

commodore and falcon are 2.25".

commodore are flanged with 2 bolt flanges at each end. They're also large and heavy.

I've used generic 2" cats on a bunch of stuff - generally catco brand. They're pretty cheap and will flow plenty for a sierra/vitara.

Steve.

[alien]

ah cool - where abouts did you find the catco cats? or just went to local exhaust place for it? How much is the average price? I've been quoted around $280 for a high flow 2" cat brand new, but i dont think the high flow is neccessary with a 1.6 behind it...

[skez]

want a high flow cat just get rid of it thats wat i did u dont need them unless your worried about the environment and u dont really have much chance of getting caught without one

[CanberraMav]

Ive used commodore. Worked well

[alien]

I'd prefer to keep the cat in tact and working =)

CanberraMav - did you run 2.25" pipe as well? or just weld to fill the gaps?

Anyone know any cars that came standard with 2" pipes which i might be able to get a cat from a wrecker?

Cheap as possible is the goal here...

[lay80n]

want a high flow cat just get rid of it thats wat i did u dont need them unless your worried about the environment and u dont really have much chance of getting caught without one

The fine is pretty big, and having watched cops at a defect station test for emissions, i would not chance it. A decent cat will not cause any noticible loss of performance, if any drop at all, for the average zook. I have seen dyno comparisons between cat and no cat on high performace cars, and as long as a decent cat is used there isnt really that much to gain. As for the environment, i would prefer to look after it and the lungs of people around me.

I have a commadore cat fitted to my zook, cheap and easy to get.

Layto....

[alien]

just been speaking to a few exhaust shops and the price for new is pretty reasonable, been quoted as low as $180 fitted!

Its been pointed out to me though that in the next week or so Cat prices are set to rise (steel costs etc).

So if anyones considering new pipes etc now might be the time eh?

[skez]

you can hollow a cat out and put a pipe through it also and yeh i wouldnt waste my money on a cat, and not worried about it as i live qld they will defect me for many other things on my sierra before they get a chance to look under it, and if ure worried about the environment maybe u get an electric car or a bike...lol

[Gwagensteve]

want a high flow cat just get rid of it thats wat i did u dont need them unless your worried about the environment and u dont really have much chance of getting caught without one

Please don't post this again. If you really do this kind of thing, just keep it to yourself.

Steve.

[skez]

just for the record i have put a 87 model engine in a late 90s model sierra so that engine didnt come out with a cat anyway but the car did

[Gwagensteve]

and that's your answer - you must match all emissions controls for whatever is newer the year of the car, or the year of the engine.

If you are defected and have to pass emissions and your cat has been gutted you will face a large fine via the EPA. there's no need to make it worse for yourself.

It's not worth it, cat's aren't all that dear.

Steve.

[DavePatrol]

i put a new exhoust in my 1.3 siera, extracters with 2 inch pipe and a hi flo sports mufler and i left the original cat under it, is it worth changing it to a better one or is the standed one ok

[Santos]

http://autospeed.com/cms/A_0630/article.html

[Gwagensteve]

I wouldn't really bother changing it now, but it might have been worth doing when you put the exhaust in.

If anyone thinks cats cost power, remember that sierras make the same power pre and post cat. Add into that the small capacity decrease and the loss of fuel octane when they went from super to unleaded and the cat just can't be costing power.

Steve.

[GRPABT1]

Seriously the High flow 2 inch cats aren't that expensive. Above 2inch they are though. Twin 2.5" cats on my commy cost me $700, a single 2 inch high flow cost me under $200 in the zook.

[mick85]

high flow cats in many sizes ranging from 2 inch to 3 inch go on ebay (brand new) for pretty cheap prices - for example you can get a 2.5 - 3inch magnaflow for an ls1 for a good price!! so keep eyes open for a 2inch high flow metal cat and snap it up

[GRPABT1]

Don't bother with a metal cat unless you go turbo.

[mick85]

if you can pick one up cheap on ebay then who cares as long as its not ceramic

[GRPABT1]

What's wrong with ceramic on a naturally aspirated car?

[mick85]

From all accounts there is nothing wrong with ceramic cats but have been told to not run them on my LS1 as they are more delicate and if knocked or bumped or over time the insides can become worn and 'rattle' - my reasoning behind a metal cat on a 4by would be because they get knocked around a fair bit more and are more exposed, even if covered by a heat shield..

[GRPABT1]

I doubt it is worth the trouble of paying more/finding a metal cat. They may not be as durable but I wonder if you knew that most cats are ineffective to the point of being pretty useless after about 50000km's? My cars both run ceramic and have done for a while and they both get knocked about, one offroad the other on a stiff as circuit racer

[JrZook]

just for the record i have put a 87 model engine in a late 90s model sierra so that engine didnt come out with a cat anyway but the car did

Was quite sure that all cars built from 1986 required cat convertors.

Dan

[11_evl]

i used a commodore one on mine. i made use of the flanges because i have my exhaust going up over chassic, taking advantage of body lift..
if your set on 2" than some of the medium cars mite use 2", ie camary, n16 pulsar, magna, so on

[Gwagensteve]

Was quite sure that all cars built from 1986 required cat convertors.
Dan

Not quite. Commercials didn't require a cat for some time after that. (early 4.5 petrol 80 series don't have cats either- and that was 1992) I've definitely seen a few unleaded sierra's that never had them. This is a bit of a grey area. It seems that suzuki applied whatever compliance plate they had lying around- Eg - we have a SWB factory ute in the club (fibreglass cab back 2 seater) that's complianced as a 4 seater carry van. This makes me think 1987 Sierras might have all been complied as commercials and so they didn't need a cat t be legal. I don't believe any 1987 sierras had cats in them; the cats only came in with the WT in 1988.

Steve.

[lay80n]

just for the record i have put a 87 model engine in a late 90s model sierra so that engine didnt come out with a cat anyway but the car did

Was quite sure that all cars built from 1986 required cat convertors.

Dan

I think it was 88 that all new passenger cars were required to run unleaded fuel, and to have catalitic converters fitted. Comercial compliance was a different story as Steve said, and a bit of a grey area. My soft top SWB is registered as a ute.

Layto....

[skez]

my old sierra was completey stock nt swb 87 model when i got it from the bloke he said it has been in the shed for years it had about 80000 on the clock so the exhaust was the original one and it had no cat they might have put the cats on when they changed there engines over when they went to wide tracks in 88

[Gwagensteve]

Yes, certainly by 1988 sierras ran cats.

Steve.

[Moph]

Well, I think my cat converter's stuffed. Did a 600km country run yesterday for work - got out at the end of it and could smell burning. Grabbed the fire extinguisher, popped the bonnet, and saw smoke streaming away from the cat!

I presume it'd become blocked with carbon and heated up on the long run. Car has been popping on decceleration over the last few months, so could have been due to too much back pressure?

Had a look underneath and the rest of the exhaust is pretty much shot too. Rang the local exhaust place twice, spoke to different guys each time. Here's their recommendations.

Quote 1:
New cat + 1 3/4" mild steel press bent exhaust + muffler = $520

Quote 2:
Wildcat 5 tri-Y extractors + cat + 1 3/4" mild steel press bent exhaust + muffler + hotdog resonator = $860

I've said myself before that I don't think extractors are worthwhile on a stock 1.3, BUUUT being that I've done a complete overhaul on the engine and intend getting a dyno tune in a coupla weeks (once it's done 5000k's on the rebuilt engine) I'm thinking I'll get extractors fitted.

Hell it's only money, right?

Will post dyno results when it's all done.

[GRPABT1]

Mate just to let you know I got a full 2 inch exhaust with high flow cat and straight through muffler (all supercat brand I think) for $500. This didn't include the price of the extractors but it did include cutting the sierra flange off the extractors and supplying and welding a GTi flange on there.

So I think you're being touched.