Cat converter meltdown....again.

[mazda2003]

About 4 months ago my 03 Tribute had a problem that was traced to a melted down front converter that plugged up the main one. I spent around $3000 fixing them. A week later it happened again. The converters were replaced for free as they were under warranty for 50000 miles. It has been about 2 months since then. Then today, Jan. 1. they went again. I am so ticked off. I know they should be replaced due to the warranty.
But the question I have is this. WHY are these failing so frequently now? I have had this vehicle for almost 5 years with no problem til recently. The one today had no check engine light come on. The last time there were no error codes the shop could detect. The one thing that the two recent failures have in common is that they both happened on humid rainy days so I am thinking there is some connection to the recent failures to humidity. The coil on plugs have checked out as being functional. I think that something is getting moisture from the humidity and causing something to happen that the shop can't figure out. Can anyone cast any light on this? Thanks from a frustrated owner. PS the car pays off in February and I was hoping to get it through then so I could sell it or trade it in. Thanks again.

[Scrapper]

are they putting OE'S cats on there? or a they putting a cheap inter changeable? also have you checked egr valve?

[mazda2003]

The EGR valve was replaced as the first time it happened the casing burst. To save a few hundred they used the same aftermarket parts that would be used on the Ford Escape which they were told would work as long as I didn't have an external oil cooler. Are they the wrong one? And what would be the connection with rainy wet days being when it happens? Thanks for your reply.

[Scrapper]

well when my granpas 1979 and when it went bad tried putting a after market he never liked it so we put O-E back on and it was the flat one that came on it. after market was round other was round. i own the 79 malibu now.

[danielsatur]

It take alots of heat to melt palladium, or platinum!

I heard of pot holes with a bad suspenshion, causing damage to the honey comb brick inside the catalytic converters.

A backfire can also damage cats.

Federal warrenty on catalytic converters is 8yr/80k miles.


See OEM catalytic converters @ http://www.catalyticconverterwarehouse.com

[adamgrant]

Converters are ment to last the lifetime of an engine.... the most common reason for converter to fail is the engine misfiring allowing raw fuel into the ehaust system ingreasing the temp. of the converter. When a coonverter failed there is a reason why, "Conveters never die, there murdered!!"

[danielsatur]

Save around $600, by blowing the cat guts out, and add an aftermarket Catalytic converter down stream.
Your going to need longer wires on your down stream H02 sensors, unless you can suppress DTC P0420's with H20 simulators down stream.