I have a 2005 F350 that is missing the Catalytic, is there and advantage to not having it?

 

Just that it's louder and illegal......

 

^^^---lol, that sums it up pretty good right there. The cats on our trucks are pretty "high flow" units, unlike the the seriously restrictive cats from "back in the day". Engine management is set up for it also, so any big gains would be at higher RPM's AND with tunes to take advantage of any increase in airflow. Some have posted there's a slight decrease in bottom end power "off the line". Of course if you were building a competition truck with an aftermarket turbo, bigger injectors, and custom tunes you would want it off there quick.

 

Sightly lower exhaust temperatures, about 100 degrees f.

 

That right there gentlemen is the only reason to pull it. Everything else is lies or misconceptions....well except the illegal part. That is a fact

 

if you bought it at a dealership without a cat, you need to go back and have them put one on it. For free of course.

 

Would 100* also apply to a cat that had been punched through, or just one that is missing?

100* seems like a good thing to me. Is this a relatively insignificant benefit, as pertaining to benefit vs gain with regards to legal exposure?

 

If you have an aftermarket exhaust (which I imagine you do) 100* isn't much. I have 4 inch turbo back MBRP with CAT in, and pulled a long grade with a 10k fiver in 110* ambient temp and barely broke 1000* egt pre-turbo. The only time I have ever seen my EGT's hit 1300 was "testing the limits" of Matt's hybrid race tune, with WOT. In my truck it is virtually impossible to get the EGT's too hot. I would say to have the cat put back in, just for legal reasons. And it does supply better bottom end power with it on!!

 

A hundred degrees would be the difference between sending molten aluminum through the exhaust and just getting things "warm". I'm not going to tell you it's alright if you pull the cat, but it won't cause any harm to your truck if you do. As far as punching it out vs. pulling it....I have no clue, mine has been removed. There has been some recent discussion about how the cats under our trucks are high-flow compared the to original design that first appeared 30+ years ago. I did notice a 200F degree drop with my truck, but results will vary between trucks.Where in your exhaust is your pyrometer probe placed? I've got mine in the manifold right next to #8, and I can hit 1400F pulling grades around Eastern Oklahoma & Western Arkansas. Last weekend took the 5th wheel to Tulsa and at 70mph pulling a couple of grades on I-40 and Muskogee turnpike I would hit 1400F.

 

My pyrometer is in the same place as yours. And I have only hit 1400 the one time when I was racing, er, speed engineering! I also only pull my 5th wheel at 55-60 going up long grades. I drive like an old man when towing, and it has kept me trouble free for 60k miles

 

I have 2 egt probes, both identical edge brand for my insight. both are in the back of the exhaust on the driver & passenger side. When using mat's extreme race tune & atlas 40 ficm tune i have seen temp above 1500 F! I back off the throttle asap & have tuned down after seeing these temps, not towing. So that 100 degrees is important to my truck/turbo/engine!

 

Hmm, that's interesting...other than I tow at 70mph on the interstate I can only think of a couple of reasons why my EGT are so much higher than yours. How heavy is your trailer? And do you happen to know what ratio you have in the pumpkin?

 

It just depends on how you do it. With my turbo, even with the slightly bigger stixs, I run cooler then a stock or just tuned truck and that's with all emissions in place as long as for the most part I'm driving normally (my normal), but not like a bat out of hell except every now and again. That's with regard to exhaust temps. I run about 10° hotter on both TFT and ECT/EOT then stock, but exhaust is slightly cooler.

There are so many variables to achieve different things that a "cookie cutter" answer isn't going to work.

Of course, on the flip side of this, I've seen locals around here that pulled the cat and didn't get any change in EGTs, mainly due to the fact that they also tuned it and they like to leave things on the hotter tunes and they do drive like a bat out of hell all of the time.

But this isn't a necessary mod even with a bigger turbo, bigger stixs, just depends on how you do it all.