morganoh

Any one has remove the Cat Converter and install a straight pipe on the mid part of the exhaust system?

I was quote $80 for a custom made straight pipe (screw in and removable)
The original cat pipe can be install back during inspection.

Do the straight pipe give a few more HP to the car and will it do any good or harm to the car.

Please advice

lennon

Remove mid pipe will definitely cause engine vibrates a lot during idling, low-end torque will diappear as you might find your car is harder to launch. However, exhaust will sounded better and better response in high speed. Typical straight pipe is more suitable for turbos. Not to forget fuel comsumption will go up too. But for $80, you should have a go to prove me wrong!

cheers

morganoh

Does it means that Low end torque need back pressure from the Cat ?

I thought with lesser resistance in the exhaust will give a better fuel consumption? how does it actually works?

cuscorex

yes,the bk-pressure might b lost,but u got a more fast-flowin on the high.another ting to note,if u r runnin w/o the CO sensor,the 'chk engine' light wil lit.

morganoh

Anyone try removing the cat before? Cos would like to seek for his/her experience before doing it myself.

EBS

1. To elaborate what bro Cuscorex say, most cat has O2 sensors and some other sensors to monitor the flow and feedback to ECU for optimal driving. Without the sensors, the CEL light up (check engine light) telling u ECU sense a prob. Some car, after prolong CEL will stop working and have to get the ECU reset.

2. U definitely lost low end torque but mid/high will be free revving. Damn shiok and good for track as u are always on high rpm.

3. Does the major tuner make such replacement cat pipes? If yes, buy from them (typically around 15000 to 20,000 Yen). For direct fit type, they have all the necessary holes for the sensors.

Enjoy

morganoh

The company that quote me $80 is Man Exhaust in Sin Ming Insdustrial Estate.
There's alot of cars modifying their cars everyday. including Audi and Pos as well.

I do not know if they know what they are doing, cos neither do I.

EBS

Flip thru the Hyper Rev magazine. The straight thru racing section (pipe) is just a plain straight pipe replacing the stock Cat. A properly designed one will fit the Cat portion exactly and has the necessary holes for the sensors to screw in. U just need to take out the stock Cat, replace it with the pipe, plug in the sensors and finished.

Man exos 'specialized' in doing exos mods. I'm not sure of their workmanship cos never tried them be4. Those Jap ones are real nice. An alternative is to operate ur mufflers as this is not too obvious as removing the Cat. Man can do those as well.

foo77

my advice is don't do it, you'll regret for it

sqflyer

Bro... a friend of mine removed his cat, CEL came on and lost of low end torque. In the end, he replaced the cat. If you drive at high RPM most of the time or track a lot, then it might be useful, but for daily driving the loss of low end torque is just going to increase your fuel consumption. A couple of other points, the exhaust will sound funny after you replace the cat with a straight pipe, can hear a slightly higher pitch flappy sound like a 2-stroke motorcycle. Also the exhaust smell is very obvious without a cat. If you ever get pulled over by TP, they can definitely "smell a rat" and might decide to impound your car for inspection. If you wanna change your cat, I think it's better to get a high-flow or racing cat as opposed to removing your cat completely.

Vanquish

That's it! I got one less mod on my mod-list! :D :D :D

EBS

Yes. Think better to try other mod first :D

morganoh

Guess this Car is very special .

Cos most of the normal 1.6-2L cars . power got even better without the cat.