what about de-cat?

[CMF_Gallardo Escobar]

hi i would like 2 know what could happen if i take off the central cat and put a normal piece of tube like the rest of exhaust. i hope the noise will not be tremendous (i've put a new cone filter and my friend can hear my car from 500mt). i would also like 2 know if i will feel some difference in terms of performance. i'm sorry 4 my bad english (i'm italian) and hope someone will answer. thanx a lot.

 

[CMF_Brendon]

if you take out the centre cat you wont feel any difference. i dont know about italy but if you have no cat on the car there are big big fines. here in australia its pretty close to $10000 for getting caught without one. as your emissions change. put on a high flow cat and exhaust with set of extractors on the front. you will notice a difference then.

 

[CMF_Pyro]

Well, thats if you have one cat. The 99 model has 2 cats. Taking out the central cat wouldnt cause emission problems (in most countries that is). Heard different stories about performance, some say they feel a slight difference, some don't. Sound level goes up, but that depends on the rest of your modifications.

 

[CMF_Yom]

All k11 have 2 cat converters. Most modern cars have similar arrangements now too.

 

[CMF_Polar]

k11 have either 1 or 2 cats, all march k11 have 1 cat. all 2000+ micra k11 have 1 cat. the rest have 2 cats.
i have to say there is a good difference from having a decat 2nd cat. especially noticable if you have a custom induction kit. after refitting a standard 2nd cat it felt like somone had stuffed the exhaust system with rubbish, it felt restricted.

 

[CMF_Brendon]

yes i know micra has 2 cats. i presumed he would put a set of extractors on. not really much point in just removing the middle cat. may as well remove the front cat as that prob causes the most restriction most likely anyway.

 

[CMF_Gallardo Escobar]

yeah today i've taken off the second cat (the central one). i don't feel differences in terms of performances but now my baby has a nice noise...now my problem is how i can take off the first one (that is under the extractors). someone says that takin it off means that my car "goes crazy", becouse there is a connector inside the cat that controls the emissions, and without that "sensor" there could be serious problems with the ecu. i would like to put a normal piece of tube instead of first cat, but i don't know what i have to do with that sensor. thanx a lot 4 answering

 

[CMF_nz_aj]

There are two sensors in the exhaust.
O2 sensor which you need.
Cat over temperature sensor, can be removed.

 

[CMF_Yom]

Do the japanaese k11 have a cat temp sensor?!?

Thats a new one (new difference that is), UK ones (pre 2000 anyway) definately don't.

 

[CMF_Gallardo Escobar]

yeah but i don't know how i can do to remove the cat without having problem