Removing Catalytic converter
 

I am thinking about removing my cat, mainly to get a better sound out of my 280z. I installed a Dynomax Thrust Turbo muffler, but was greatly dissapointed about the sound.
I know this topic has been beaten to death, but before I do this I really would like to hear from guys that have done this and theire experiences posetive/negative. What can I expect in terms of sound, performance, milage.
Will less backpressure affect the engine in a bad way? In theory less backpressure should make the engine run easier...hence more power and even make the engine run cooler. But what have you guys experienced. Long term affects?
New header and upgraded exhaust is no longer an option due to the crazy amount of work needed to replace it...the dude that told me that these cars are easy to work on...should be used as a pinata :075:

Just removing the cat won't do much for power unless it was plugged... maybe a couple hp? Used in combination w/ less restrictive intake & complete exhaust, yes, it's more helpful. As for sound, yes it will make your exhaust louder.

I used to run my 280zxt w/ a test pipe because it sounded amazing. :D But I eventually got fed up with my clothes smelling like a nasty old truck whenever I drove it.

My test pipe:

http://memimage.cardomain.com/member...8_279_full.jpg

:045::045:Always great to hear your opinions, NismoPick! I truly appreciate your feedback. However, there must be other Z drivers on this forum that has removed the cat. Would love to hear from you guys as well.

NismoPick, did you notice a difference in milage? I did my research, but it was not conclusive. Some people stated better gas milage, while others thought it would decrease the milage.

Do you think it can be bad for the engine in the long run...knowing that the engine was designed to run restricted?

Smelly clothes...that was a new one, but really something to consider. How bad was it?

How much louder? I really would like a deeper sound, but not too over the top.

I owe you a beer NismoPick, and if you play golf and visit Las Vegas, then lets hook up.
:023:

I remove all the cats out of every car I've ever had, and many on my friends. In my expirence it has made the car run better. A few more hps, a few more mpgs and a louder lower tone. But the sound depends on alot of other things. The only bad is if you have to smog the car.

Federal (not CA cars) pre-79 280Z's didn't come with a cat...mine didn't.

Mine is a 78 280z and yes a CA car. Anywhoo, took my car to the muffler place that installed my Dynomax muffler, with the intention to remove my cat. Guess what? Wouldn't do it. Said it was not legal. Took it to another muffler shop...same response. But this guy told me if I cut off the cat and dropped the car off, he could weld in the the straight through pipe.

Now I'm just tempted to drill a bunch of holes in my muffler...but that would just be too tacky...and dangerous......what to do, what to do...:017:

I coulda told ya that... :023:

It is illegal for shops to remove emissions equipment... though somewhat hypocritical about it, the US government does require everyone to be emissions compliant. If a shop gets busted for compromising emissions on a car, they will get shut down, and the tech will likely get sued.

If you don't want your emissions parts, take them off yourself. :D

I had to go to about 10 different shops in tell I found one that wouldn't put a cat on it. All you have to do is cut the cat off and tell them it is an off road veicle only. Then they will do it. When I got the exuast done on a 4 runner, the shop made me take off the plates, cat, and the emission sticker. They also made me sigh a waver saying that it is an off road truck. As far as your car makeing your cloths smell, that most likely means an exaust leak.

Thanks Zordietrying

So much "trouble/redtape" to prevent us from enjoying our cars...makes me want it more:armata_PDT_35:

Seriously, my car is not the fasted out there, but for a 33 year old car...still alot of fun...just would have been soooo much better with some more rumble

The reference to smelly clothes was given by Nismo. I can picture the free flowing unused gas/firespitting without the cat:biggrin:, but never thought about the smell...

However, when I got my car, the exhaust was leaking. Found one bolt missing at the intake manifold and others were loose. Let me tell you...what a PIA to tighten them. I had so many cuts on my arms after I was done it wasn't even funny. Worth it though. I don't know if this was due to sloppy work by PO or if they just come loose after 33 years of rattle'n shake. But if anyone have an annoying and dangerous exhaust fume it wouldn't hurt to retighten them. Just be prepared for some #@%$#& and have fun with it:023:

Where?
 

I fab'd it. :D

Went to my local Midas muffler shop in my old mechanic outfit and asked if they had any 2.5" scrap exhaust pipes laying around. Got a couple pipes for free99. I've also done that for the flanges & gaskets... but AutoZone / your local parts store also sells flanges and thinner (cheaper) pipes. Just make sure to get galvanized or stainless steel.

Oh... and you need a quality MIG or TIG welder.