Is my Cat. gone bad.

[Jeeplander]

Have any of you guys lost you power due to clogged cat. converter. I had the engine rebuilt after a split a piston 8 months ago. the tj is losing power on the hills more then normal. I changed plug, wire, cap, trans fluid, oil change, air filter. still got the same problem...... any suggestions.....

 

[RLitwin]

It might be easier to have a shop check it out. They should be able to tell what is wrong within an hour. $75-$100

You can do the repair to save $ if you want.

It could be air flow (clogged cat), fuel system, electric system.

 

[ExpoMike]

You mean the 2.5L actually had power??? :elkgrin:

I haven't had it happen to me but I have had it happen to friends. The vehicle will run okay until placed under a heavy load or high RPM's. Depending on how bad it is clogged, it can be a minor loss or power or a major one.

You can try check the cat by tapping on it with something metal and seeing if you hear a rattling sound from inside. If you hear something rattling from inside, the cat is typically toast.

 

[njtaco]

Take its temperature. It should be hotter on the downstream end. If the upstream end is hotter (by a lot) it is usually clogged.

Um, use a thermometer, not your hand...:costumed-smiley-007

 

[Jeffb79]

When it's dark out, get the engine up to operating temp. If the cat is clogged, it should start to glow. Doesn't always though.
Have you noticed it idling funny, harder to start up, etc?

 

[Jeeplander]

not really, starts are clean, every now and then its has a rough idle. I just notice losing power on hills and a little bad gas millage. Don't have the pep it should.

 

[njtaco]

Fuel filter, fuel pump pressure, dirty/corroded wiring???

Any idea why the piston "split"? Is this a common failure? Is it possible you are running lean? Can you run it with a scan tool so you can see what is going on?

Just throwing ideas out there...

Oh, you have checked the timing, right? And the engine is warming up and operating in closed loop?