My 1993 F-150 XLT has been destroying catalytic coverters. They have been lasting only aprox. 6000 mi. I had the exahust upgraded about 3 years ago using 3" piping and a big Catco converter. It has failed three times since then, the dealer replaced two of them at no charge, but the last one I had to pay for. The dealer says the problem has to be with the truck producing too much heat causing the converter element to melt and breakup. The truck never heats up even pulling a trailer. It has never run so well!! Does anyone had any similar problems? I plan to have the a tuneup done soon with special attention to the smog system.

smilie(':\'(')
https://www.ford-trucks.com/dcforum/Images/cry.gif Thanks, Jack(my.gypsy@verizon.net)

 

coughremovethecatforgoodcough

 

Hahahaha.... well said...
What he said ^^

 

 

My truck does the same thing, 1991 ford f-250, 4x4, 5.8. No modifications to anything, stock exhaust.

I go through a cat a year, no one can find anything wrong with the truck, it runs like a top, no problem anywhere......except for the cats going out like clockwork.

Aside from removing it, since I cant get away with that......has anyone else had this problem and solved it?

 

Could you just punch it out and put it back on? I have heard some will still pass an inspection like that.

Tony Warren

 

I'd buy a new cat.....take the test, and then remove the cat, saving it for the next test.

 

Excess heat is the destroyer of cats. If your truck is running rich to the point where it is burning fuel in the cat, that will burn it out in a hurry. Running too high an octane gas can eventually cause the same effect as can having the timing set wrong.

 

I have a 92 f150 flareside single cab with a 302 and e4od tranny. When I purchased the truck it had the first catalytic converter melted so I just ended up replacing the 2 of them with magnaflows catalytic converter and also replace the O2 sensor. That was about almost a year ago. Now the truck performance is not there and sometimes I get a burning smell and it's not oil burning or something electrical am guessing that it could be the catalytic converter. Now my question could be what causes the catalytic converter to melt. Any help would be appreciated since my 93 f350 is going thru a heart transplant.

 

There could be several issues including you are burning oil and it's enough to basically kill the cats..... IMHO would run a compression leakdown test to verify. The PCM may be the issue as well.....Production calibrations have an “inferred catalyst temperature protection model” which constantly calculates the temperature in the hottest part of the hottest catalyst. This calculated temperature is based on many PCM parameters, such as engine speed, load, ingested air mass, time, inlet air temperature, EGR flow rate and many others. When the catalyst model calculates that the catalyst temperature is about to exceed a level that is safe for the catalyst (generally around 1650 deg F), the PCM will richen the A/F mixture as necessary to lower the exhaust gas temperature and cool the catalyst. This richened A/F ratio will decrease power output, but is absolutely necessary to keep the catalyst from being permanently damaged, if the PCM gets bad info or the software has an 'issue" it can easily, consistently and once too many times over or under richen the A/F mix...making what a software engineer would call, "An erroneous conclusion"... burning up the cats and may also cause "Vale Tuliping"...basically warping the valves.