I've noticed what seems to be an excess amount of heat coming from the drivers side floorboard area when I'm driving around. I don't know if the passenger side floorboard area is seeing the same kind of heat since I never ride on that side. I've assumed for the longest that it was just the tranny causing that until I was under the truck today and noticed the cats are directly underneath the front floorboards. The heat has been noticeable for around a year or so.

My gas mileage seems a bitworse than normal, but I haven't tracked it well enough to say for sure. I don't drive the truck frequently enough to make an accurate assessment - when I do drive the truck there is one of three different trailers behind it so the gas mileage varies pretty substantially.

I've also noticed a high pitched whine/whistle coming from underneath the truck in that general area for the last year or so - not sure if it has anything to do with the cats though.

Truck has 114k miles on it and had some terrible fuel system issues for quite a while that have now been worked out (replacement of fuel injectors, o2 sensors, fuel tank, fuel filter, and fuel pump).

What exactly are the tell-tale signs of the cats getting clogged or going bad?

 

http://www.aa1car.com/library/converter.htm

Try this, it runs it down pretty good.

 

Cat issues identified could be of glowing hot cats in the dark, struggling on start up, random surging idles, black soot/smoke blown on start up or rev. Will get gradually louder.

 

I think mine are both bad i tap on the cats and they both sound like its dust inside... I stomped it going down intertate to get up to speed and i heard metal rattling in exhause and also big cloud of black smoke came out. It sounded like metal coming through the pipe and shooting out.

 

can I use after market o2 sensors on my truck ?

 

It sounds like you definitely have the symptoms of a busted catalyst.

You can, but sticking with the OEM Bosch are your safest bet for accurate readings.

 

Yea, I would love to stick with the best but unfortunately this f150 is just my hunting truck and I dont have alot of money to put in that truck at 225,000 miles ya know. There is just 2 cats on there right? it looked like it was 4.

 

Are the cats welded on a 99 ford 150 from factory? I don't see a clamp to take the rear loose

 

4 cats I think and yes they are welded.

If your cat is broken up real bad then you might need mufflers too. The peices from the cat can lodge in the muffler and restrict the flow, symptoms are about the same.

 

I was wondering do I necessarily have to put 4 cats back on there ? Couldnt I just use 1 on each side ?

 

OEM cats are welded in place.

You can put 1 cat per side should not be a big issue with registration and will not be on the emissions sniffer.

 

Thanks Darren I ordered the 94106's and 4 new o2 sensors i changed 7 out of 8 plugs and got all new cop's I don't want this to happen again.. lol I cant get the plug in back on the passenger side out the socket wont bite.. after I get all that done im putting the new cats on

 

Yea sucks that they are welded on, so much harder to replace

 

I know that two of the cats are in plain view, because I had them replaced with straight pipe, but where are the other two? I ask because my floor boards are hot at times also and I do occasionally get surging idles. I know that when I had the two cats removed that they were clogged, and that was 3 years ago. I'm wondering if my other two are also bad so I can get them replaced....

 

One each side close to where the pipe connects to the manifold. It's where the exhaust drops down. The other two are closer to the front of the muffler, those sit level.