Alright. So the only problem with the 86 z31 I just bought supposedly, was the catalytic converter was faulty. So I cut it out. All 4 of the bolts stripped and broke off even after being hosed with wd40 and penetrant. So I cut it out with a sawzall.

The next day, I went to autozone and test fit every piece of pipe and adapter I could to fill in the gap where the cat used to be.

I settled on a piece of flex with an adapter to the rest of the exhaust. Its leaking very badly and its reeeeeal loud, I'm sure you can imagine as the leak is a mere 15 inches from where the two headers come together!!

Now. I'm going to the exhaust shop today. Should I have them replace the cat? Or have them straight pipe it better than my half assed job?

 

#1: DON'T EVER USE WD40

#2: DON'T EVER USE "FLEX EXHAUST PIPE" ON A Z (it deserves better)

#3: The exhaust shop will surely make you put a cat back in, as it is "against the law" to go cat-less. They don't want to get in trouble, so they gotta cover their butt.

 

I know it deserves better. It's a temporary fix until I figure out what to do.

If it would be just fine I can tell the shop its an offroad only car not street driven, so they just straight pipe it.

What I was wondering is if the cat is needed for backpressure? This car has no pick up right now.

Now. Would I be better off without the cat? Or should I get a new one?

 

Telling the guys at the shop "it's for offroad use only" isn't gunna fly too well... how'd you get it to the shop?

Rule #4: Don't try to weezle guys at a car shop, unless you know them very well.


Just buy a high-flow performance cat & have them put it in... be done w/ it.

 

i said to hell with it and bought the monza/ pacesetter exhaust. it was only 130 bucks including shipping. ebay<3

 

still won't include a cat.

 

there nwill be a whole LOT more performance after the cat is replaced-- astuck cat makes slow turd. fix flow, it follows, more FAST. save your z from other car mfg parts--the ones that are for our cars actualy work, especiallty if you make sure airflow happens. just like diesels,only much more fun.

 

update:

took the car to a local muffler shop.
the guy took one look at my car and said 'sweet man...what year?'
so I didn't even bother cooking up some story about why I didn't need a cat.
not only did he own a ka-t 240sx, but had a turbo supra and...you guessed it. used to own a 260z.
I told him what I needed, and 4 hours and 80 bucks later he had all the piping from the header to the monza muffler section welded and high temp sprayed.

who needs a 200+$ catalytic converter when I have this guy!!