Purchased a 2002 Mountaineer 4.6 AWD

[Donald Haulsee]

Thursday I purchased a 2002 Mountaineer with a 4.6, AWD and it seems like every option available except for a sunroof. It's red with 133,000 miles and body wise and interior wise is in very good condition. It came from the Durham NC area. I paid $850 for it and towed it back to tidewater Virginia.

Yes, I was buying a problem child. The owner had given up on it as it died one day and ever since then will start, run ragged and die as soon as it is put into any gear. No codes either.

Well, after a lot of troubleshooting I can say it has clogged catalytic converters. Today I released the Y-pipe from the manifolds and allowed the pipe to drop back about 1/4". I've driven it about 2 miles since then and while noisy, it did ok. I've never seen a vehicle be as screwed up as this one was from plugged cats. I've seen them sluggish but the was a whole new level.

So now the hunt starts for new cats. I'm not sure if I will buy a direct fit unit or just cats and weld it together. At this point I'm not sure if the cats in the downpipes are plugged or if it is just the single one at the rear. It had essentially no exhaust coming out the tail pipe.

 

[Rick]

Nice find! $850 and it just needed cats? Sounds like a heck of a deal. Enjoy

 

[Mike65]

Welcome.

 

[BrooklynBay]

Welcome to this forum!

 

[Mbrooks420]

The real question (and issue) is why they clogged in the first place. Unless there is another issue the cats should last the usable life of the vehicle.

 

[Donald Haulsee]

I would like to find out why they are clogged. I'm not sure how to figure that out. Coolant is full. It has the aluminum intake. There are no stored or active codes except for a code 34 air bag. I find that odd as I expect it to have some O2 sensor faults from the clogged converters. I suppose there is a chance its clogged downstream of the O2's but I don't think it likely.

 

[Donald Haulsee]

Update:
The passenger side cat matrix was shattered. The driver side cat was fine. The pieces from that went thru the Y-pipe and clogged the cat just in front of the muffler. This 3rd cat was fine, just clogged with debris from the passenger cat. The pieces of matrix were clean so I have no idea why the upstream cat shattered. I had an 89 Mustang GT that did the same thing though and Ford replaced the cats under warranty.

I cut the down pipe apart and put universal cats back in. Getting the individual pieces aligned correctly to be leak free when I welded it back together was a bit tricky but I got there. The engine is now very responsive and smooth. I've put about 200 miles on it.

I had to clean the connections under the seats to clear air bag codes 33 and 34. I also had to replace some bulbs, turn signal flasher, a boot on a CV axle, anti-roll bar links, and do brake pads.

The only issue left is a whine that comes in at about 2000 rpm. It matches engine speed. I think I probably have a belt tensioner going bad. It could be the PS pump or the torque converter though but I don't think that likely.

There are two things that don't work. The lock keypad is completely dead but I have three keys and two functioning remotes. The reverse proximity alarm doesn't work either. I probably won't bother with these.

 

[Mbrooks420]

Often a misfire will shatter them if it gets bad enough. You get an excess of fuel going into the pipes and touching off late and it essentially detonates inside the cat. This happened to me driving my escape home with a failed coil on plug.

I assume a stuck injector could do this as well.