Lessons Learned - Clogged Catalytic Converter

[brus brother]

Having learned much from browsing USMB pros and novice input, I was able to solve a buddy's headscratcher.
2002 Ford E250 van suddenly lost power. At first, could barely make it up a hill and then could barely go along a flat straight road. Checked fuel pressure thinking bad pump or filter. Checked/disconnected a few of the coil on plugs as some had been replaced but not all.
At idle it ran fine. Under load, just died.
In a parking lot, revved the engine and a hose blew off the valve cover.
Yup, the exhaust was completely blocked by a disintegrated catalytic converter.
Disconnected the exhaust and roared home (varoooom) to vacuum out those pieces that were causing the blockage.
Reconnected the exhaust with a new gasket. No codes thrown and for now will just run it as is.
When it warms up outside, may run a scope up the y to determine which side was affected and see if there are any more pieces waiting to come undone.

Edited February 13, 2016 by brus brother

[Fairtax4me]

Haven't heard of that being a big issue on those.

Is there any kind of impact damage to the cat(s)?

[mikaleda]

Its a ford the problem is circled on the front jk

I've actually seen that happen a few times, no real reason why but the honeycomb style catillist the domestic car manufacturers use will do this.

[Bushwick]

Ford cats won't tolerate running rich or lean too long. Gas additives seem to be the no.1 preventable cat-killing issue, even if they marketed as "cat safe". I lost a cat in a 92' SHO and 86' Cougar years ago, and the Cougar had gas additives, SHO was apparently in need of a sensor the earlier ECM diagnostics didn't alert to.

 

Be sure to identify the cause before slapping another cat in there, as it'll likely do the same thing again if it's running funny. I remember dumping money into a new cat for the SHO, only to have the entire casing glow as bright as 12v cigar lighter element.

 

If Y pipe has a cat at each side, and one where both sections connect (Ford usually ran quad cats pre/post for factory dual exhausts, so I'm guessing you have 3 total with Y pipe), figure on replacing the entire Y section or cut old cats out and weld in a universal(s) as Y sections can get expensive even for the crimped corner piping that won't last long, but factory piping with aftermarket cats can last longer and will cost less. Also, if one of the cats melted but didn't dislodge, and other is breathing freely, it'll have excessive back-pressure on one side, and possibly excessively high EGT which is bad. Removing the cats might cause it to run rich constantly, which is also bad, so you'd be better off not putting it off longer than needed.