cat decat... confused!

[Rutger]

hi every1,
this might be a stupid question but i dont have a clue about the cat or decat on the starlet exhaust systems. i looked at the exhaust thread,,, this confused me even more!

can anyone post a pic up of the cat? and how a decat is fitted please?

thanks!

Rut

 

[MJA]

i don't have pics at the mo, but a "decat" refers to the exhaust downpipe. In stock form, starlets have a cast downpipe which houses a catalytic convertor with two lamda sensors, one before the catalytic convertor and one after.

The downpipe is located in the engine bay, to the right of the turbo in front of the radiator. a standard downpipe will be a rusty brown colour with several heatshields covering various sections.

a "decat" is an aftermarket downpipe (usually stainless steel) with the catalytic convertor removed and the bottom lamda sensor removed.

This is to increase the flow of exhaust gasses, thus reducing turbo spool up time

 

[Rutger]

o right, so a downpipe is the same part as a decat then? or that not right..
my friend tried to explain...
mani->turbo->downpipe->cator decat-> exhaust section??


Thanks,

Rut

 

[riko666]

in this scenario cat = downpipe

 

[MJA]

yeah, they are the same thing.

the full names are either a "decat downpipe" or a "exhaust cat downpipe" the difference being a decat downpipe has no catalytic convertor and an exhaust cat downpipe does.

the word "decat" is just an abbreviation

 

[Rutger]

yay i understand
thanks for the help guys

Rut

 

[Adam_Glanza]

on some cars the catalytic converter is inbetween the centre pipe of the exhaust but on the starlet there in the downpipe

 

[MJA]

That's a pic of my WEPR decat downpipe.

as you can see, it's hollow stainless steel with no filter (aka catalytic converter) inside it

 

[Starlet_Sam]

MJA, the cars only have one lambda sensor, the second one is a temperature sensor.

 

[MJA]

oh, i thought they had a before and after cat lamda

 

[L900CMC]

http://img504.imageshack.us/my.php?image=brakepadsanddiscs3280jz5.jpg

Thats a standard cat and decat

 

[Rutger]

Thanks every1 for the input,
this helped a lot

Rut

 

[Nick@TD.co.uk]

oh, i thought they had a before and after cat lamda

Nah starlets only run on 1 lamda sensor then the bottom one is a heat sensor, makes decatting alot easier as we dont have to worry bout engine lights, really simple thing to replace tho and a great mod all round adds alot more driveabilty to the 4E.

 

[thomatt12]

Isn't it that catalytic converter restricts the exhaust flow so it means the car's performance would increase without it.

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[gayan_GT]

well i used to have a aftermarket de cat earlier and now i have the original de-cat but gutted... i must say the initial power is much better than the aftermarket one... but as for the top end... it sucks cock...

 

[Dane_Bristol]

Nah starlets only run on 1 lamda sensor then the bottom one is a heat sensor, makes decatting alot easier as we dont have to worry bout engine lights, really simple thing to replace tho and a great mod all round adds alot more driveabilty to the 4E.

With my new odecats you are able to choose to keep the exsisting heat Sensor if needed, alternatively there will be a bolt supplied that will just bung up the unwanted hole if need be.