Cat Delete?

[BenBB]

You can definitely rule out clogged cats, I had an '83 Chevy stepside with an anemic 305 that wouldn't start one day; replaced plugs, wires, air filter, HEI module, fark I don't remember what else but finally cut the damn cat out and it ran fine (well relatively, for a GM product, let's just say it started up at least). So when the platinum pellets eventually load up all they can take they can't breathe at all, and it won't run at all. I like @FordTechOne's solution. You need a Whipple and a JDM tune.

 

[CoronaRaptor]

It almost sounds like it’s running lean and you’re smelling the exhaust becoming (extremely) hot after being under load. With LT headers, you’re increasing the volume of air that can be pushed through the engine during the combustion cycle. More exhaust out allows for more intake air to fill the cylinder during the subsequent intake stroke. More air requires more fuel, and the PCM can only compensate so much. With the factory exhaust manifolds, that increase in exhaust flow (from the LTs) is theoretically impossible, so the PCM will in most cases not be able to properly account for it. This is especially true under full throttle, where the system reverts to open loop (default tables) instead of closed loop (O2 readings).

You may want to consider getting the truck tuned to compensate for the LTs, especially if you’re going to be running it hard. Lean conditions blow engines, and I don’t think you want to join that club!!

Thank you for that explanation, makes perfect sense, I was hoping you would throw your input into the equation!

 

[CoronaRaptor]

You can definitely rule out clogged cats, I had an '83 Chevy stepside with an anemic 305 that wouldn't start one day; replaced plugs, wires, air filter, HEI module, fark I don't remember what else but finally cut the damn cat out and it ran fine (well relatively, for a GM product, let's just say it started up at least). So when the platinum pellets eventually load up all they can take they can't breathe at all, and it won't run at all. I like @FordTechOne's solution. You need a Whipple and a JDM tune.

There’s no way I’m putting a Whipple on with this many miles, but the kid in me wants to listen to you, ha ha.

 

[Jakenbake]

There’s no way I’m putting a Whipple on with this many miles, but the kid in me wants to listen to you, ha ha.

Rebuild it and then throw the whipple on.

 

[Gary E]

From the discussion, two things come to mind:

At 152,000 miles, depending on how hard the engine has been worked thru its life, maybe it's showing its age.

Have you consulted with SW about their cats, ie. life expectancy, similar symptoms they've experienced, etc.

 

[Canuck714]

What tune are you using to run with Longtubes?
It is probably a combination of the truck working a little harder (creating more heat) and the ****** winter fuel up there.
I can tell you from experience that my supercharged truck was very fuel sensitive. Mexican (Pemex) smelled funny and would sometimes cause CEL when running hard. Valero 93 felt like 87 and Petro Can winter fuel did too...

 

[CoronaRaptor]

What tune are you using to run with Longtubes?
It is probably a combination of the truck working a little harder (creating more heat) and the ****** winter fuel up there.
I can tell you from experience that my supercharged truck was very fuel sensitive. Mexican (Pemex) smelled funny and would sometimes cause CEL when running hard. Valero 93 felt like 87 and Petro Can winter fuel did too...

I'm not running a tune and never have for over 11 years now. My dealer told me, "do whatever you want with that Raptor and we will warranty everything, but don't put a tune on it or...." They honored everything even when I showed them doing jumps in the dunes, etc. I think maybe with its age it's time to put a tune on it. I will look into it.

 

[CoronaRaptor]

From the discussion, two things come to mind:

At 152,000 miles, depending on how hard the engine has been worked thru its life, maybe it's showing its age.

Have you consulted with SW about their cats, ie. life expectancy, similar symptoms they've experienced, etc.

Yes, I've consulted SW, they don't think there is an issue with the cats, but just wanted to see what others thought. I agree, she is getting older, but still runs great and pulls hard, but who knows you get used to stuff over the years.

 

[Jakenbake]

I'm not running a tune and never have for over 11 years now. My dealer told me, "do whatever you want with that Raptor and we will warranty everything, but don't put a tune on it or...." They honored everything even when I showed them doing jumps in the dunes, etc. I think maybe with its age it's time to put a tune on it. I will look into it.

At least start with some datalogs to see where you are currently at.

 

[The Car Stereo Company]

insert smart ass comment here

i deleted my cats a long time ago. left them with the ex wife. now i dont need to clean a litterbox anymore