355 F355 5.2 and tubi test pipe ( cat replacement )

You will ...

get a very rich smelling exhaust ...
a very much louder exhaust note ... even then the bypass valve is closed
and a constant bother of CEL

Some 355 (especially 2.7) do not run well with cats removed. They rely on a bit of back pressure in the exhaust to run right.

 

First I've heard of this (which is not to say it isn't real). Why don't 355's with free-er flowing mufflers have similar problems? Can you elaborate on what you mean by they "do not run well"?

 

yes the car runs better with stock cats or high flow cats.

ive run all the configurations. including straight pipes. and car runs better with cats.

to answer OP question. yes you will have strong exhaust smell. i ran straight pipes for two seasons and couldnt take the smell anymore.

so put the stock cats back. and the car idled and smoother.

i am running a Nouvalari SS right now.
i think it’s the perfect in between balance. and a fair price point

 

yes i have a recording. i can send to you by what’s app. what’s your number.

no issue with fitment/quality. the nouvalari is a good exhaust.
yes my car is a 1997 5.2.

 

my current setup right now. and has been the best balance since owning the car almost 8 years.

ive done everything:
stock headers
fabspeed headers
stock cats
hollowed cats
straight pipes
stock ypipe
Nouvalari catless ypipe
stock exhaust
Challenge fabspeed exhaust
Nouvalari SS exhaust.

my current configuration i feel best balance.
Fabspeed headers
Stock cats
Nouvalari catless ypipe
Nouvalari SS exhaust.

 

the ypipe is on top.

it’s what connects to the bypass valve.
so when the bypass opens, most of the exhaust passes through the yipe.

so i’ve found a good balance to have stock primary cats below. and then the catless ypipe above.

 

I put a full de-catted Fabspeed system on my 5.2 Spyder. I should have kept the high flow cats on the car….when I would fire up the car in the parkade, the exhaust fans would go on (to exhaust the parkade) and this always pissed off the building management. Also, the exhaust stinks. Engine light was always a problem too although I was very happy with the Fabspeed product. With top down, it was a little too loud on longer trips. Funny….I still have all the cats and original headers/exhaust…I should sell them. Cheers.

 

De-catted 5.2 (or 2.7) 355 is asking for all kinds of issues, of which CEL is one.

 

+1

It made my eyes water, too, when standing near the vehicle. I switched to high flow cats.

 

I knew I would have an engine light going in when I purchased (same with any de-catted brand). A piece of black electrical tape eliminated that. I would purchase Fabspeed again and always recommend the product, it’s artwork.

 

Personally I think they sound a bit more refined with high flow cats as well.

I had test pipes on my F1 355...it was stinky for sure. Great rumble though.

With high flow cats, you lose the rumble but when you're on it, it sounds cleaner IMO. Added benefit of not needing to shower after every drive.

 

Before the 1980's no cars had cats and somehow everyone was able to drive them without going blind or needing to shower.

 

Both my 2.7 355's ran/run fine with primary straight pipes. Never ran cats, so don't know how it runs with primary cats, but I believe @INTMD8 documented a 10-15 rwhp gain from 200 cell cats to straight pipes (on 2.7). An additional 10 rwhp gain from OE catted Y-pipe to customer de-catted Y-pipe.

 

I removed the cats on my 5.2 a couple of years ago and think it was the greatest improvement the car has ever had.
I installed mini-cats on the rear O2 sensors so no CEL.
In the summer you really notice how much cooler the engine bay is.
The only thing you have to do is go though the re-learn process for the ECU.

 

I have Larini primary and secondary cat deletes on a 5.2 car with a capristo. I do not notice the exhaust smell issue at all- I think I would notice it, no one who has ever seen the car has commented either. The car is slightly louder than I’d like with the valve closed but I think sounds better than it did with race cats and It is perfectly driveable at highway speeds. The car has 90 deg mini cats from fabspeed but they do not prevent the secondary 02 cels. I have not spent a lot of time playing with them so it’s possible this is solveable but most people I have spoken to told me
It’s unavoidable. The car shoots flames on high rpm upshifts- not necessarily a reason in itself to make the change but does not hurt .

 

Life expectancy is a lot higher these days.

 

More like before the mid 70's. All these ******* () ranting about smell and watering eyes would never have made in back in the 60's muscle care days. Cars running trips and dual quads were so rich you could light the exhaust with a match. That's the way they built them back then. And then we'd but bigger jets int he carbs just 'cause.

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Hey, I'm still kickin' around.

 

I think most of us would think Sports cats are better for sound.