Hot Cat

[ACRucrazy]

Buddy just sent me this pic from his shop.

[johniew398]

yeah - you might say HOT!

[C.J]

Looks a tad hot.

[FLATOUT]

Wow

[VYPR BYT]

nuclear meltdown

[Sybil TF]

Clogged?

[Bugman Jeff]

Running just a teeny bit rich I'd say.

[JonB ~ PartsRack]

And you cannot blame the CAT..... something is fueling that heat, and it aint the cat substrate!

If that vehicle had a coincidental fuel leak even feet away: POOF !

[ACRucrazy]

Ya, it was a Focus with a coil only firing 2 cyl.

[MtnBiker]

So, what does that mean? Lots of unburned fuel going out the exhaust?

[v10enomous]

Stay off the dry lawn and leaves by the soccer field...

[100]

What makes a converter become red hot and/or melt the brick (thermal melt down)?

Converters will get red hot when excess fuel is introduced directly into it, along with sufficient oxygen to burn the fuel. This is not a problem with the converter itself, but the result of a problem with the fuel system or ignition that allows unburned fuel to pass through the engine and then travel down into the converter. If the root cause is not corrected, the new converter will melt as well.

Common causes of a melted converter are:
1) A three-way plus air vehicle running rich, and when the air is injected into the converter, the rear brick will melt as the excessive fuel now has enough oxygen to burn inside the converter,
2) Vehicle is running rich with an exhaust leak, and when the air is drawn into the exhaust pipe and is combined with the excess fuel, it will burn in the converter,
3) The vehicle has a misfire. When the air-fuel charge leaves the combustion chamber without firing, it will travel through the exhaust pipe and burn in the converter.