Catalytic Converter Problem

[Texasgirl]

I have just replaced the catalytic converter in my 1997 Ford Ranger for the 3 time. I had a rebuilt engine put in 2 years ago. The people at the shop that replaced the catalytic converter told me I should never have to replace it again (they told me this the last two times as well). The engine light goes off and on at different times. I was having problems with the truck dying and not staying on a few months after the installation of the new motor and took it to another shop. They could not figure out the problem and finally bypassed my computer. Does anyone have any ideas about what I should do besides just drive it off a cliff???

 

[Natedog]

Sounds like too lean or too rich....resulting in a plugged converter. How do you 'bypass' the computer? Not sure what the heck they meant by that! It needs the computer to run because it is EFI. Converters should last alot longer than yours are.

 

[MAKG]

If the check-engine light is EVER on (or even if it isn't), run the self tests. It may give you a direction to check.

It's not unheard of for catalytic converters to get done in by a chronically weak body ground. For instance. It needs diagnosis.

 

[Mutant Pony]

Anything going through the exhaust that is not supposed to will damage the cat. Oil,antifreeze,raw fuel.

 

[Wicked_Sludge]

knowing how the cat converters are supposedly failing will help. are they fouling out? plugging up? melting? what?

 

[anupaum]

We had a Cavalier that went through TWO catalytic convertors in less than 6 months because the oil control rings had failed, so the engine was pumping oil through the convertor and wrecking it.

From up here, it sounds like you may be dealing with a similar issue--something is getting into your exhaust that doesn't belong there!

 

[Texasgirl]

knowing how the cat converters are supposedly failing will help. are they fouling out? plugging up? melting? what?

Every time I have to replace the cat converter, it is dislodging from its housing and lodging in the muffler, causing me to have to replace the muffler as well. As for how the computer got bypassed, I have no idea. That's just what the mechanics told me. The mechanic's ordered a computer (supposedly) but decided it wasn't going to fix the problem and so did not install it. The problem I was having was the truck would not stay on. I took it to the shop and after two weeks, they called me and said it was ready. I got in it to drive off, and again it wouldn't stay on. After a few more days they told me they had bypassed it and it was working, but that I would never be able to have it tested or diagnosed. I have been told before it could be burning too lean, but how is that adjusted?

 

[Ozwynn]

I think they are blowing smoke up your ass. A 97 Ranger wont run without the computer.

Did they bypass the cat maybe?

 

[MAKG]

And if the cat is disintegrating, perhaps it's melting. Rich mixtures can do that -- I've seen a cat glowing red hot at simple low speed cruise, from a loose spark plug wire (causing a misfire in one cylinder). Just the fuel from that made it glow. And though this was an OBD-I vehicle, it had a downstream oxygen sensor, and didn't trip the CEL.