Signs of clogged catalytic converters!?!?!?

It's a 5_0 HO

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Dec 20, 2006
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Here lately my 95 GT has been bogging down after driving it for a few (30 mins or so). Anyways my friend told me that my catalytic converters my be clogged up. Is this true? What are the signs of them being clogged or is this have something to do with something else? Any help would be appreciated!!!
 
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If they're clogged, the car would definitely bog down. It wouldn't miss like an ignition problem, just have no power and may sound strange. I've never heard of a cat 'clogging' though. My stock pre-cats went bad at 110k miles. The internal element actually became dislodged and was rattling around sideways inside the cat body which blocked the flow. Under normal driving you could barely tell. When I punched it, the car sounded funky like a WRX but went nowhere. I smashed both elements out of the precats with a crowbar which was a lot more fun than it should have been. No more problems after that and I still passed emissions.

Still, I'd do a tunup before dropping the H-pipe. You may need it anyway. Don't forget to clean the MAF. Do that first.
 
If they're clogged, the car would definitely bog down. It wouldn't miss like an ignition problem, just have no power and may sound strange. I've never heard of a cat 'clogging' though. My stock pre-cats went bad at 110k miles. The internal element actually became dislodged and was rattling around sideways inside the cat body which blocked the flow. Under normal driving you could barely tell. When I punched it, the car sounded funky like a WRX but went nowhere. I smashed both elements out of the precats with a crowbar which was a lot more fun than it should have been. No more problems after that and I still passed emissions.

Still, I'd do a tunup before dropping the H-pipe. You may need it anyway. Don't forget to clean the MAF. Do that first.

That is what mine does as long as i dont punch it it runs fine but as soon as i punch it bogs like hell and the check engine light comes on. Im gonna have to check on it. That won't hurt the car will it?
 
A clogged exhaust is not nice to the motor. I've lost a cat before and the motor eventually shut down (out in the boonies on a trip, trying to make it back to civilization).

The best way to test is with a backpressure gauge. They're not common so if you choose you can:

Put a vac gauge on a manifold vac port. Start the car and hold the revs at 2500 or so. Note the vac gauge reading once it stabilizes. Keep it like this for 30 seconds or a minute and if the reading drops, that suggests you have an exhaust restriction. You might need to wait to do this until the car acts up if the blockage is mild.
 
A clogged exhaust is not nice to the motor. I've lost a cat before and the motor eventually shut down (out in the boonies on a trip, trying to make it back to civilization).

The best way to test is with a backpressure gauge. They're not common so if you choose you can:

Put a vac gauge on a manifold vac port. Start the car and hold the revs at 2500 or so. Note the vac gauge reading once it stabilizes. Keep it like this for 30 seconds or a minute and if the reading drops, that suggests you have an exhaust restriction. You might need to wait to do this until the car acts up if the blockage is mild.

thanks. im off tomorrow so i will go get a gauge and see if that is my problem. Sucks to hear bout your breakdown. I have had a few of those in my days.
 
A clogged exhaust is not nice to the motor. I've lost a cat before and the motor eventually shut down (out in the boonies on a trip, trying to make it back to civilization).

The best way to test is with a backpressure gauge. They're not common so if you choose you can:

Put a vac gauge on a manifold vac port. Start the car and hold the revs at 2500 or so. Note the vac gauge reading once it stabilizes. Keep it like this for 30 seconds or a minute and if the reading drops, that suggests you have an exhaust restriction. You might need to wait to do this until the car acts up if the blockage is mild.

This reminded me that I also did the vacuum test before dropping the H-pipe. All the signs were there and very obvious.