Cats & Decats



  • Anyone had any dealings with the ebay sports cat? Either the more expensive 100 cell or the cheaper 200 cell :

    100 Cell 2" - £155
    http://www.ebay.co.uk/itm/Custom-Chrome-Racing-Stainless-Sports-Catalyst-100-Cell-CAT-11-L-x-2-Inlet-/400465979052?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5d3da1e6ac

    200 Cell 2.5" - £70

    http://www.ebay.co.uk/itm/UNIVERSAL-HIGH-FLOW-EXHAUST-SPORT-CAT-200-CELL-2-5-64MM-CAT250-/310653910911?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item48546a7f7f

    Am I right in thinking that the OEM cat is 400 cell?

    Anyone have any emissions results with a decat in place? And what difference you noticed when it was done?

    Thank you :)



  • Cant offer anything Im affraid fella as not been tempted by any?,I would consider a decat pipe!! (not clever and not paticularly green tho ) :shock: Its just the hassle of 'ON and OFF' each year for test just for a 1-2 bhp ??? increase (realworld)! I would guess that fuel consumption would….........increase due to extra flow and air/fuel ratio?...........decrease due to lack of restriction????

    De cat emissions?? CO=up, HC=up, Lambda=...?? to what extent I know not? would vary, dependant on the general health of your 'lump'

    Loads of more informed members on here, will i'm sure? give you direction on this matter :P

    PS Is that second link/thread correct? its not highlighted on post, 'TWEEKS' are quite expensive too imo :( kev b.



  • I only decat mine and replace at MOT time, if yo use stainless bolts all round its an easy job each year.

    the only worry I have is its from demon tweaks so its like a slightly performance halfords jobby



  • Altered the OP, hope it works now :)

    That's probably true about the power and fuel consumption. Would prolly need some sort of fueling computer? Apexi, emanage or whatever? Again prob for little gain. Almost just talked myself out of it haha.

    I could make the decat as I have the pipe and could cut out some flanges too but I really can't be bothered to keep putting it on and off all the time, hence looking into the sports cats. So hmmm no point getting one for it to be rubbish after 12months. So hopefully someone has experience of them :)

    There was a huge hole in the pipe after the cat when I first got the car, sounded heaps better and felt like it revved 10x better, I liked that lol.



  • I decatted my ZE and left it off for 3 MOT's in a row and failed none of them. Just my experience :cheers:



  • @44c76e3251=barrywhite21:

    I decatted my ZE and left it off for 3 MOT's in a row and failed none of them. Just my experience :cheers:

    Good to know!

    What year car do you have? (assume its a uk car, which would give you max limits of CO : 0.3% & hc : 200?)

    edit : Just had a quick scan, you have a 93 so those limits should be correct, so a nice clean engine then :)



  • Wow! must be a very efficient and healthy ZE you're running :D

    Speaking of cats etc, I have a question about the manifolds on the K8, on the 'chipfetcher' Im running at mo, 1996 1.8 v6 GS the exhaust manifolds are cast standard ones and are quite slim in profile, with the O2 sensor at right angles to the down pipe.

    On the K8 i bought off member 'Teamrealsmooth', the manifolds are again cast but are very 'bulbbus'? and as the O2 sensor is missing, I can clearly see inside at what appears to be 'catalyst cell'??? as the engine is on a dolly i have peeked up both down pipe connection flanges to see the same cell on both manifolds, so its not had a different manifold replaced during its former life in a mexy? also the O2 sensor mount is at about 30 degrees and pointing forwards? :? Could the latter be from an 'import' with more stringent emission regs, having 2 small manifold catalysts and a further common one down stream at the junction of the 'Y' piece???
    Could I ask which type members have and does anyone have any info on this 'cat type' manifold? kev b.



  • @6f443adb7c=blackmexyv6:

    I can clearly see inside at what appears to be 'catalyst cell'??? as the engine is on a dolly i have peeked up both down pipe connection flanges to see the same cell on both manifolds

    Thats interesting, so if I have read that right there are 2 cats (1 for each bank)

    Edit : alsoooooo, does anyone know the standard bore of the main cat, it it 2"?

    Cheers, :)



  • Correct, well sort of, there would be three in total, one in each manifold, and a third where they join at the 'Y' branch down stream. WHY, THATS STRANGE?

    Tonight I decided to remove one of manifolds and inspect closer, it has the look of a 'catalyst cell' but it doesnt see to be 'coated' with a catalising coating, I think they are restrictions or possibly 'flame traps' installed to increase temperatures at the location of the O2 sensors as they work in this small 'campartment' between the exhaust valves and the rolled up mesh that I may have mistaken for a catalyst cell????.

    I hope someone can inform or correct me on this matter :oops: just out of interest really! kev b.

    PS ; If I get chance, i will take and upload a pic of said items?



  • Just popped out to garage, my '96' cat bore is 55mm (2 and 1/8th inch old school ) internal diameter. :D kev b.



  • @1896154ba0=blackmexyv6:

    Just popped out to garage, my '96' cat bore is 55mm (2 and 1/8th inch old school ) internal diameter. :D kev b.

    Excelant thank you! :cheers:

    Might as well go 2.5" if doing a system I recon :D



  • @c30be710ce=blackmexyv6:

    Tonight I decided to remove one of manifolds and inspect closer, it has the look of a 'catalyst cell' but it doesnt see to be 'coated' with a catalising coating, I think they are restrictions or possibly 'flame traps' installed to increase temperatures at the location of the O2 sensors as they work in this small 'campartment' between the exhaust valves and the rolled up mesh that I may have mistaken for a catalyst cell????.

    Yeah strange indeed, I know the Toyota MRS has pre-cats in the manifold but Mazda are usually a fan of having them in the downpipe.

    Kinda hope they are cats really as you can still remove them for less restriction and still have a cat!

    @c30be710ce=blackmexyv6:

    PS ; If I get chance, i will take and upload a pic of said items?

    Awesome, will be good to see what it all looks like :)



  • Further internet trawling has uncovered that the 'BULBBUS' manifold cats, are 'CALIFORNIAN', they are '3 WAY, WARM UP CATALYTICAL CONVERTERS' so there you go!!! As they are made of a rolled up mesh affair, there is quite a large central hole in the middle of each cell? I would guess too that they rob about 3 bhp each??????? :shock: If I ever have to swap over engines, I will be swapping manifolds too? :o



  • Ricco, do you have the slim-line manifolds (O2 sensor in-line with manifold) as I do on my current mexy? as they have 'NO' cats in them?

    Its the BULLBUS ones (O2 sensor pointing forwards) that contain the 'warm up cats'! I think you could probably chisel/ragg out the mesh on the bench, but certainly not in situ on car, and further more, there may be a sub routine in ECU used at warm up? that may confuse the 'BRAIN' (or throw up a code) if you do indeed remove them? NOT sure :shock: :oops:

    Having grief with my 'photobucket' account which is delaying pic uploads! :(



  • PICS OF 3 WAY WARM UP CATS (Equipe?) Removed from front bank, heat shields also removed, Notice casting code K6 ?

    Catalyst cell in manifold before downpipe flange ?

    Looking up into manifold

    How it sits on K8 california lump! ?



  • Cant really get camera in there but here's a pic of the slim 'NO CAT' manifold on my 1996 V6 GS! Notice 'NO' bottle shape and a lot slimmer profile? Wonder wether downpipes are interchangeable? as California/equipe 3 way cat, warm up manifolds are a lot deeper?



  • @afcb766e1a=blackmexyv6:

    Ricco, do you have the slim-line manifolds (O2 sensor in-line with manifold) as I do on my current mexy? as they have 'NO' cats in them?

    Really good pictures there!

    Fortunately I have the 'sliml design with no precat. I guess the Californian precat is due to their tighter emissions standards for back in the day ;)



  • Took the plunge! Removing current catalyst and fitting this ETS de cat tommorow :o


    Slightly smaller bore, 2", and it appears to have rifled, perforated, sleeve and surrounding wadding? so it should flow better than CAT but not be overly 'shouty' ?

    ![]([url][img]http://i1297.photobucket.com/albums/ag28/blackmexyv6/P160513_2110_zpsa8f67666.jpg[/img][/url]

    Very well made and finished for £36.69p? will assess longevity next March when I replace catalyst for MOT? :shock: Shame to hide it under car!)

    May record vid/soundtrack for B4 and AFTr ? :?



  • :bigok: :D :D :D :D Piece of wee wee to fit! even used both old gaskets
    (although gobbed em up with 'mufflit') Replaced bolts with stainless and coated threads with hi temp silicon as I did that 2 years ago on steel bolts I just took off and threads were like new under the nuts :P

    Conclusion: like 'NIKE'…....DO IT!
    1. Id say about 10% increase in noise? (standard bosal back box)
    2. 20% ? increase in throttle response/driveability and 'smile' width :P

    ![]([url][img]http://i1297.photobucket.com/albums/ag28/blackmexyv6/P170513_0938_01_zpsdd47825a.jpg[/img][/url]

    Power to weight ratio has increased too :o (prob 1/2 the weight of old CAT).
    Well pleased with my tiny financial outlay! slight guilt about polluting planet? kev b.)



  • Sounda like your well happy! :cheers: Any pops and bangs yet?? ;)

    Does it smell rich once its up to temp now or not too bad?

    Does it throw a light up on the dash after or is that also cool?


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