I'm curious what anyone's experience has been with catalytic converter warranties. I have 2006 Expedition with 66k that I just finished getting a misfire fixed in. I had it at the dealer twice about two weeks ago to get three coils and three plugs changed. I had to find the fourth bad coil myself, afterwards, to get it 100% fixed.

Now I'm getting a P0420, which probably means the cat is shot. Will the misfire problems void the 80k warranty on the cat? I'm not paying another $1,500 to get this fixed, so if the dealer won't cover the cat I'm considering just getting rid of it and getting something new. My personal opinion is that it should be covered, which I think can be justified from a couple of angles (as in the cat shouldn't have failed in the first place, or if Ford couldn't fix the misfire problem in one visit how is the average guy supposed to prevent this problem in the first place).

I'd appreciate any thoughts or experience anyone else has had with a similar issue.

Thanks.

 

You might be covered under the Federal Emissions Warranty program.
http://www.epa.gov/oms/consumer/warr95fs.txt

 

I think you're right. Looking at the law, it says this:

What Reasons Can the Manufacturer Use to Deny a Warranty Claim?

If your vehicle is within the age and mileage limits for the
applicable emissions warranty, the manufacturer can only deny coverage
if evidence shows that you have failed to properly maintain and use
your vehicle, causing the part or emission test failure. Some
examples of misuse and malmaintenance include the following:

* vehicle abuse such as off-road driving or overloading; or

* tampering with emission control parts or systems, including
removal or intentional damage of such parts or systems; or

* improper maintenance, including failure to follow maintenance
schedules and instructions specified by manufacturer, or use of
replacement parts which are not equivalent to the originally
installed parts.

The plugs are not scheduled to be changed until 100k (owners manual), and the coils are not a recommended maintenance item at any point. I'm expecting I won't have any issues when I drop it off tomorrow. We'll see!

 

It might help to have a printout of that file in-hand when you go there.