About how long did your stock cat last?

[PunkST]

I know a lot of us have swapped out. But for thise who ran it for a decent amount of time, how long did your stock downpipe/cat last. Is it still going well?

Im at 97000 now and been tuned for the last 60k wondering if its starting to go..

 

[Erick_V]

13 months after I bought the car the stock cat decided it didn’t want to be a part of my car anymore. Not sure if my crackle tune had anything to do with it or I was just unlucky. I suspect the latter. Since then replaced with a Whoosh 3’ Catted DP

 

[LastMK7]

A tune shouldn’t affect the cat, even pop tunes as claimed by either Stratified or Dizzy (cant remember who came out and stated it). Ive never heard of a cat going “bad” under normal conditions.

 

[TyphoonFiST]

Until I took it out at 45k to go to a Gen2 GTX2860R to find out the Factory/ ford cross threaded the upstream O2 sensor when I took it out. Thank god I was going to a high flow or I'd would've been up secretion tributary without means of propulsion!

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[LastMK7]

Until I took it out at 45k to go to a Gen2 GTX2860R to find out the Factory/ ford cross threaded the upstream O2 sensor when I took it out. Thank god I was going to a high flow or I'd would've been up secretion tributary without means of propulsion!https://uploads.tapatalk-cdn.com/20191005/68db77234a2e8b86753c2
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That does suck, but fortunately it was an install error and not an issue with the cat itself

 

[Erick_V]

A tune shouldn’t affect the cat, even pop tunes as claimed by either Stratified or Dizzy (cant remember who came out and stated it). Ive never heard of a cat going “bad” under normal conditions.

For sure. There are hundreds if not thousands of people running Flash/ProTunes from reputable tuners like Stratified and Dizzy. I may be the only person that blew a cat out and had a crackle/pop tune. Don't think there is a correlation between the 2. I have an MBRP CBE and my exhaust would go from loud to stock quiet then loud then quiet before it blew the cat. Either way it gave me an excuse for an aftermarket unit.

Until I took it out at 45k to go to a Gen2 GTX2860R to find out the Factory/ ford cross threaded the upstream O2 sensor when I took it out. Thank god I was going to a high flow or I'd would've been up secretion tributary without means of propulsion!

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One of the studs that connects the dp to the catback was cross threaded from factory on my car. Fun stuff with Ford lol

 

[scooter123]

Per Federal Law everything between the exhaust port and catalytic convertor outlet must be warranted for 10 years/100,000 miles. It's why you will find these components are ALWAYS Stainless Steel.

BTW, type 409 Stainless will develop a rusty looking coating when exposed to heat but it's not actually Rust, it's Ferric Oxide. The difference is that Rust increases in Volume as it develops and Ferric Oxide does not increase in Volume. As a result rust continuously flakes off and erodes while Ferric Oxide sort of seals the surface and protects the part from further oxidation. Back in the 70's and 80's a lot of front y pipes were made using type 409 stainless and those y pipes would generally last for 20 - 30 years before needing replacement.

 

[PunkST]

Its more the internals of the cat. Im trying to locate my missing milage.

 

[TyphoonFiST]

Per Federal Law everything between the exhaust port and catalytic convertor outlet must be warranted for 10 years/100,000 miles. It's why you will find these components are ALWAYS Stainless Steel.

BTW, type 409 Stainless will develop a rusty looking coating when exposed to heat but it's not actually Rust, it's Ferric Oxide. The difference is that Rust increases in Volume as it develops and Ferric Oxide does not increase in Volume. As a result rust continuously flakes off and erodes while Ferric Oxide sort of seals the surface and protects the part from further oxidation. Back in the 70's and 80's a lot of front y pipes were made using type 409 stainless and those y pipes would generally last for 20 - 30 years before needing replacement.

Its 8yrs..80k..FYI.

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[scooter123]

Apparently the weenies at the EPA have been receiving some gratuities, because back in the 80's it was 1000,000 miles / 10 years.

Now concerning a failure in a catalytic converter. In a modern laminar flow converter a failure typically results in a rattle at idle as the element rattles inside the casing. If you dont have a rattle odds are better than 95% your converter is just fine. if you are experiencing a drop in fuel economy then look to your right foot or have someone scope your intake valves. Because on the FiST a loss of economy is usually due to one of two things, too much Joy for the right foot, or too much crud on the intake valves.

I can also state that when the converter in my 85 Monte Carlo SS failed the only effect was that rattle, had no loss in power or degradation in fuel economy. BTW, worked for the manufacturer that made the front y pipe for the 83-88 Vette so I grabbed a couple of the reject outlet pipes and used them to build a 304 stainless wide mouth "test pipe". Replacing the rattling converter with the test pipe also had no effect on power or fuel economy.

 

[PunkST]

My guess could be intake valve crud. Im near 100k witb no catch can ever being on the car.

 

[MagnetiseST]

My partners lasted 20k in his first FiST before it decided it didnt want to convert anymore, and Ford replaced it under warranty.