Is it recommended to remove precats on my 360?

I am interested in input from any pros, or members that have more experience.

I have a higher mileage (40k miles) 360. Currently the Entire exhaust is off except for headers and gearbox is out for other maintenance so access is great. I have the gaskets and time so that’s not an issue.

Would y’all recommend to your customers removal of the precats (either decat stock part or replace the headers with precatless aftermarket part) as a preventative against damage from ingestion of precat material. I do understand this is rare, but potentially catastrophic issue. If not, would you do it on your own car if you planed to keep it.

No disrespect to any members but I’m looking for input from folks that have more experience than reading posts and working just on their own single 360 (like me and many people on this site).

Thanks for any advice,

-ray


Sent from my iPhone using FerrariChat

 

Always better to upgrade to a better manifold. The stock units are prone to failure. Tubi is the product we install. They are expensive..but worth every penny.

 

Thanks for the input. The failures are in precat, or is there another problem with 360 manifolds.


Sent from my iPhone using FerrariChat

 

The manifolds has 2 failure points..the precats and the fact the metal tubing basicly melts..causing leaks etc..

 

In my experience, the later year model 360s will have a check engine light from the no pre cat headers. I have a client that wanted his headers replaced while other work was being performed and we had a check engine light that would no go away. O2 sensor code. We tried a lot of things before we put his stock headers back on and the light was off after that.
I don't know when the break is for later cars that will have an issue, just relating my experience.

 

Thanks for the responses and sharing your experiences. Interesting to get different perspectives. I’m still on the fence as to what to do.


Sent from my iPhone using FerrariChat

 

What year model is your car?

 

2002. Owned it for 11 years. 40kmiles. Purchased it without main cats.

Was using mini cat extenders with only occasional CEL from downstream O2 sensors.

Planning on a tune from Trevor that will eliminate the downstream O2 sensor issue. With precast only it’s pretty noticeable, I’m not happy that it will be louder and smellier with them removed.

I don’t have to worry about smog/emissions inspection I’m in Massachusetts. Just can’t have CEL’s. No plans to sell.

I really don’t want to spend a fortune on expensive new manifolds and cats because I am in the midst of big maintenance projects on it now, and frankly the car runs stronger without them. But I would change or modify the manifolds if it is recommended to protect the engine.

Thanks
-ray

 

My 2003 just rolled over 40k miles recently. I had the transmission out just before it rolled over. I could not see anything visually wrong with mine so I left them alone for now. My exhaust is all original OEM.

Image Unavailable, Please Login

 

Thanks for the input I do appreciate it. mine look good also. Don’t know if anyone can say that periodic inspection can avert a catastrophe.

I’m my case I wonder if the reduced back pressure and absent strainer effect of main cats deleted will reduce the possible ingestion and allow the fragments to just blow downstream. That assumes the precat itself doesn’t prevent fragments from traveling downstream.

For piece of mind I’m leaning toward gutting the stock manifolds. If I don’t like the noise or smell I will consider replacing the bypass pipes with high flow cats in the future.

Further comments are welcome.

-ray




Sent from my iPhone using FerrariChat

 

I have zero proof or evidence of this but it I feel that many issues with exhaust happen early in a cars life because the part was just not up to the job. I have seen many of these with many miles and no cat issues. I have in the past been involved in a number of warranty type issues, some that have happened years into ownership but still at low miles. (not covered under warranty) All of the issues are within 3000 miles or so. Some are 200-300 miles. As time passes, I see less and less issues with failed exhaust. You are correct in the fact that the cat material will not let the debris pass. The cat breaks up from the exhaust valve side and that is why the debris gets back in the engine.
Just my thoughts.

 

Thanks for the input. I appreciate you sharing your experience. So your theory is like natural selection, those unlucky cars with defective parts have been selected out early. Very interesting that cars you have seen with failures have been after low miles.

What advice would you give your customer who came to you for guidance on this. Sounds like you just gave it.

-ray


Sent from my iPhone using FerrariChat

 

I have a fortune cookie slip taped to my desk. "If it ain't broke, don't fix it." While I am a strong proponent of preventive maintenance, I am not sure headers fall under that as the failure rate is very low. Like I said, I think the bad ones have failed already and the rest are strong and likely to work for a very long time.

I go back to my previous post about having zero evidence to support this. It is just my experience.

 

Of the 360 and CS in my circle, I have seen two out of three CS losing their cats.

One has a disintegrating precat material in the header and needed to be replaced with another used header. That one barely has many miles on it.

The other one at 40K miles has the failing main cat converter itself. for what ever reason, the main cat on a 360 is made with two sections and the main O2 sensor is positioned in between the two sections. The front section has come loose from the shell and pushed itself into the O2 sensor and caused a CEL. Replacement of the Cat converters using Fabspeed rebuilt one caused a lot of headache with CEL. Finally solved with mini-cats on the rear O2 sensor.

On my own 360, if it ever failed, I would just put the stock Ferrari headers and cats back on.

 

I understand your response is anecdotal, and your theory is based on your observations.

But this is why I wanted people with more experience than n=1. Especially since generally it seems pretty rare it’s hard to get enough data to determine trends. Thanks for sharing your experience.

My dad a WWII vet always said “leave well enough alone”.

A Russian academic i knew for years before she passed said there was an old Russian saying “the enemy of good is better”.

-ray


Sent from my iPhone using FerrariChat

 

Thanks for sharing. Those are Concerning numbers. Interesting how it further supports Ferrari tech’s observations about lower mile cars.

It’s the precat failure that is most concerning. Did that car go on to have engine damage? How was it diagnosed?

-ray


Sent from my iPhone using FerrariChat

 

I did the 5 year service on that car, as well as a clutch and RMS on that car. That required the cat converter to come out. Then a look into the end of the header revealed the precat material in flakes. So that header came out and this is what was seen:

Image Unavailable, Please Login

After it was replaced, the car went on to have a good life. But, the owner owns a large number of fun cars and the CS does not see much use after that.

 

Thanks for sharing. So in your experience how would you advise an owner. Remove the precats, leave them alone?


Sent from my iPhone using FerrariChat

 

I would not remove the precat because it would cause a CEL.
I would check the condition of the precat anytime you have a chance to look into the exhaust, and at major service time
I would only replace with OEM parts

And if you are DIY and can stomach non-stock stuff, then delete the pre-cat and have your ECU modified to remove the CEL.

 

What a shame.

Next time Pm me and I can adjust the thresholds for the CEL and save the hassle of reverting!



Sent from my CPH2145 using Tapatalk

 

Early software versions ( on early cars ) didn't have very good calibration setup for component protection so would cause more issues. Later firmware was better in this regard and yes I can adapt later software revisions to work on any model year, thus benefitting from many things including smoother idle.

Sent from my CPH2145 using Tapatalk

 

Just another data point. My CS has 10,500 miles. Last year a major was performed and the precats were checked. They were in perfect condition.

 

Hey Trevor I’m already in queue for a flash with Sam.

Cool set up you have now to do it remotely.

-ray


Sent from my iPhone using FerrariChat

 

Any idea how they were “checked”? Visual inspection, checking for movement or migration…


Sent from my iPhone using FerrariChat

 

Well this is interesting. I looked at the cats and they look ok. I measured the position of the cat (distance to the bottom edge of the manifold. Then I lightly pressed on the precats with a rubber handle of a hammer. They both traveled in by 1/2 inch with almost no effort. A light tap with the same rubber handle sounds like they are loose.

Is this normal, my gut tells me no. With these puppies rattling around in there it’s probably just a matter of time.


-ray

Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login


Sent from my iPhone using FerrariChat