My new ride Vitz 2006, fresh import

[Mortal]

Both CATs are present in the front side of the vehical.

The removal of 1st CAT is very easy, just need to remove the manifold and get the CAT out.
The removal of 2nd cat takes a bit longer, first you need to get the exhaust piper out, from just after the manifold till the silencer, there are two dholkies in that pipe, the dholki near to the front side has CAT, in order to get the CAT out you need to cut that dholki and get the CAT out after that you need to take it to welding guy who welds the dholki and bring it back to original position.
If you read this with all the pics which i have attached, you will understand better.
Hope i have explained well.

[syed-shoaib]

Both CATs are present in the front side of the vehical.

The removal of 1st CAT is very easy, just need to remove the manifold and get the CAT out.
The removal of 2nd cat takes a bit longer, first you need to get the exhaust piper out, from just after the manifold till the silencer, there are two dholkies in that pipe, the dholki near to the front side has CAT, in order to get the CAT out you need to cut that dholki and get the CAT out after that you need to take it to welding guy who welds the dholki and bring it back to original position.
If you read this with all the pics which i have attached, you will understand better.
Hope i have explained well.

Wow. Well done bro. So we have to break dholki to get CAT out. What about sound? Howz your ride performing now?

[roms]

Shoaib this is the first thread for new shape vitz which is very comprehensive. keep it up buddy

[roms]

Wow. Well done bro. So we have to break dholki to get CAT out. What about sound? Howz your ride performing now?

When the CAT is out the exhaust gases will be expelled quickly, after removing u will be experiencing a slight noticeable gain in acceleration, and it will make life easy for engine a bit as well.
Sound will be like bhurrrr when your rpm will be in the lower band, there is a tip to totally get rid of this sound. Buy a muffler of earlier version of vitz/yaris i.e. 2001-2004. remove the genuine one and put in the garage and put the other one on and u will be delighted

[Mortal]

Wow. Well done bro. So we have to break dholki to get CAT out. What about sound? Howz your ride performing now?

Dear Shoaib,
AOA,
Yes breaking dholki is the only way to get the 2nd CAT out.
As far as sound is concerned, there is change of 7 to 10% only, if you are a light footed driver you will not feel the change and if you press the foot hard then you can feel the sound of zoooooo only when you press the foot hard. But if the windows are closed then the sound is very very low...... its near to nothing.
And the performance............ don't ask its just great, i can feel the acceleration has become much much better and engine is not heavy anymore, my CAT was chocked around 50% so i can feel the difference a lot.

[Mortal]

When the CAT is out the exhaust gases will be expelled quickly, after removing u will be experiencing a slight noticeable gain in acceleration, and it will make life easy for engine a bit as well.
Sound will be like bhurrrr when your rpm will be in the lower band, there is a tip to totally get rid of this sound. Buy a muffler of earlier version of vitz/yaris i.e. 2001-2004. remove the genuine one and put in the garage and put the other one on and u will be delighted

No bhurr bhurr sound from my ride bro, my mechanic told me to take the dholki to the denter after removing the cat so that he brings is back to its original shape, this will decrease the sound, when the job of denter is complete the job of welder starts.......
The sound is not much bro, its not irritating or annoying... more genuine i guess
In my opinion the sound is much better as compared to the sound when CATs not removed.

[roms]

No bhurr bhurr sound from my ride bro, my mechanic told me to take the dholki to the denter after removing the cat so that he brings is back to its original shape, this will decrease the sound, when the job of denter is complete the job of welder starts.......
The sound is not much bro, its not irritating or annoying... more genuine i guess
In my opinion the sound is much better as compared to the sound when CATs not removed.

The bhurrr sound doesn't come because of the deshapping or holes and obviously it is welded again, it comes because of that hollow empty chamber changing the flow of exhaust gases. That is somehow removed if we change the muffler.
But obviously genuine is genuine and i am happy that you didn't experience the weird sound

[Mortal]

The bhurrr sound doesn't come because of the deshapping or holes and obviously it is welded again, it comes because of that hollow empty chamber changing the flow of exhaust gases. That is somehow removed if we change the muffler.
But obviously genuine is genuine and i am happy that you didn't experience the weird sound

The only function of dholkies is to make the sound, isn't it? That is why they are present there, otherwise it could be a straight pipe i guess.

[roms]

The only function of dholkies is to make the sound, isn't it? That is why they are present there, otherwise it could be a straight pipe i guess.

Muffler's muffle the sound, the stock mufflers are not hollow from inside they have some restrictions and chambers to control the noise cancellations. Its kind of destructive interference which muffles the sound. Every car make has different kind of mufflers used depending on engine headers length and down pipe diameter. When the CAT is removed the flow of exhaust gases and the pulses are different when the hit the first resonator of muffler. That's why the change of sound happens in this case. Free flow exhaust are a different story

[syed-shoaib]

Shoaib this is the first thread for new shape vitz which is very comprehensive. keep it up buddy

jazakAllah bro. It has become possible only due to the great contributions of our beloved fellows. Many thanks to Allah for letting us to contribute into the ocean of information in pakwheels.

regards,

[syed-shoaib]

@Mortal. Awesome work bro. Do check and update us with the change in mileage. I will do this too. And excellent suggestion from roms bhai.

@roms Sir, if the sound is bad, and we get the dholki of old shape vitz. Does that dholki contain a CAT too? Will we have to remove that CAT too? or is it CAT-less?

regards,

[syed-shoaib]

@roms. Sir also update if you know that will if effect the sensors? I mean the sensors like o2 and others. The CAT removal will change the dynamics of air exhaust. Will it effect the correct calculations of sensors?

[roms]

@Mortal. Awesome work bro. Do check and update us with the change in mileage. I will do this too. And excellent suggestion from roms bhai.

@roms Sir, if the sound is bad, and we get the dholki of old shape vitz. Does that dholki contain a CAT too? Will we have to remove that CAT too? or is it CAT-less?

regards,

Shoaib bhai CAT and muffler are two different things. Muffler is the last part of exhaust system and it is present in every car/bike. Whereas CAT is not present in all vehicles. Cars in Europe/ USA biuld cars which have CAT because they have to meet the International standards of CO2 emissions. New vehicles in paksitan like honda and other imported vehicles do have CATs in them. CAT is used to convert the toxic gases into other friendly form by initiating a chemical process because of catalyst element

[roms]

@roms. Sir also update if you know that will if effect the sensors? I mean the sensors like o2 and others. The CAT removal will change the dynamics of air exhaust. Will it effect the correct calculations of sensors?

No affect on sensors but on environment but if CEL comes up than it is the O2 sensor but it is highly a unlike scenario. There are 02 emulators in the market available easily which can do the job

[Mortal]

@roms... Thanks bro you have been very helpful

[Mortal]

Muffler's muffle the sound, the stock mufflers are not hollow from inside they have some restrictions and chambers to control the noise cancellations. Its kind of destructive interference which muffles the sound. Every car make has different kind of mufflers used depending on engine headers length and down pipe diameter. When the CAT is removed the flow of exhaust gases and the pulses are different when the hit the first resonator of muffler. That's why the change of sound happens in this case. Free flow exhaust are a different story

Thank You for detailed explanation bro,
I have checked online there are many Mufflers available online, i tried to find a genuine one but failed to find it, not present in BILAL GUNJ....
Please elaborate, different mufflers have different sounds?
Where can i find the genuine one from lahore?

[syed-shoaib]

Shoaib bhai CAT and muffler are two different things. Muffler is the last part of exhaust system and it is present in every car/bike. Whereas CAT is not present in all vehicles. Cars in Europe/ USA biuld cars which have CAT because they have to meet the International standards of CO2 emissions. New vehicles in paksitan like honda and other imported vehicles do have CATs in them. CAT is used to convert the toxic gases into other friendly form by initiating a chemical process because of catalyst element

Ahan. Got it bro. JazakAllah.

[tyrone_40]

All things are present in my car other than side speakers on dash beam

Where exactly is the restraining board? Can you post a pic, please if possible?

Thanks in advance

[roms]

Thank You for detailed explanation bro,
I have checked online there are many Mufflers available online, i tried to find a genuine one but failed to find it, not present in BILAL GUNJ....
Please elaborate, different mufflers have different sounds?
Where can i find the genuine one from lahore?

Sir it depends upon ur luck, when i had vitz, i found the original muffler of vitz 2004 and it was lying with a silencer wala. The owner of that vitz/yaris gave it to him because he installed an Chinese aftermarket exhaust :P. So i bought from silencer wala in 1600 rs. keep looking for it and i am sure u will find it.
Yes different mufflers have different sounds because they are designed according to the engine, headers and pipe diameter. It is not a big deal they vary on different vehicles. It is a trial and error thing if you experiment a muffler from other vehicle because the pulse mechanism is different and hence some times more cancellation will occur and sometime it will be bit noisy.

[roms]

Ahan. Got it bro. JazakAllah.

thanks bro, and keep us updated on ur vehicle