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do i have a cloged cat? or whats wrong with it? by hookdonspeed
Started on: 12-19-2014 06:23 PM
Replies: 13 (306 views)
Last post by: hookdonspeed on 12-22-2014 12:54 PM
hookdonspeed
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Report this Post12-19-2014 06:23 PM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
88 2.8 5speed, was running great, then this just `happened` outa nowhere, within a day or so it got 4x worse.. figures would happen just as im finishing up my list of items needed for the 3.4TDC swap...

so anyway...
car runs a little rough at idle, if i try and drive it, it 100% looses power at like 2500-3000 rpm(doesnt stall, just falls on its face almost like i hit the brakes), if sitting still and i rev it, it sounds like the engines having `trouble` getting the rpm's... doesnt sound like its missing, just like its really struggling....

ima pull the o2 sensor out tomorrow and see if it seems to breath better or not.. i just changed the fuel filter, gas was nice and clean on both sides of it, so i do not belive its a fueling issue.


any other ideas?
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dobey
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Report this Post12-20-2014 10:42 AM Click Here to See the Profile for dobeySend a Private Message to dobeyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Shake the cat and muffler and see if either one rattles like the insides are moving around. If so, one is clogged. Also test the EGR and make sure your manifolds aren't cracked.

Did it get louder too? If so, I'd lean toward the cracked manifold.

Do you get decent flow out the exhaust tips? If so, probably not clogged. If only decent flow out one side, then muffler could be partially clogged. Mice maybe? They like mufflers.
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hookdonspeed
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Report this Post12-20-2014 10:57 AM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by dobey:

Shake the cat and muffler and see if either one rattles like the insides are moving around. If so, one is clogged. Also test the EGR and make sure your manifolds aren't cracked.

Did it get louder too? If so, I'd lean toward the cracked manifold.

Do you get decent flow out the exhaust tips? If so, probably not clogged. If only decent flow out one side, then muffler could be partially clogged. Mice maybe? They like mufflers.

Muffler? What is muffler? :P. It has the sprint manifolds, def not cracked. An exhaust leaknwouldntnmake thencar fall on its face when driving least I couldn't see how it would?

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hookdonspeed
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Report this Post12-20-2014 11:30 AM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
just pulled the O2, revs better, and a drive around my block was a car that could accelerate alot better then it could with the o2 installed. so clogged exhaust it is... being its 2 1/2" from downpipe back, i assume it has to be the cat. (dont see mice being an issue as the car is in the cold, and we are not known for mice like that around here)
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sardonyx247
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Report this Post12-20-2014 03:20 PM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageClick Here to Email sardonyx247Send a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
The way to test for a clogged CAT is with a VAC gauge, if you don't have one,.... a vac gauge is a good thing to have.
But you hook up the gauge and watch the vacume, should be around 18in or so, rev to 2000rpm and HOLD it there, the vac will drop and then go back to what it was before, if the cat is clogged the vacume will go lower and lower.


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hookdonspeed
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Report this Post12-20-2014 05:22 PM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by sardonyx247:

The way to test for a clogged CAT is with a VAC gauge, if you don't have one,.... a vac gauge is a good thing to have.
But you hook up the gauge and watch the vacume, should be around 18in or so, rev to 2000rpm and HOLD it there, the vac will drop and then go back to what it was before, if the cat is clogged the vacume will go lower and lower.


yes, or you can pull the 02 sensor and see :P (my vac gauge isnt local atm)


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Report this Post12-21-2014 03:24 AM Click Here to See the Profile for nickwstpSend a Private Message to nickwstpEdit/Delete MessageReply w/QuoteDirect Link to This Post
I just had to deal with a clogged exhaust due to mice and the car sitting in the previous owners barn for a few years. Car felt like it had no power and when you gassed it, and fell on it's face.

I got under the car and tapped on the exhaust with an allen wrench until I thought I found the clog, took an angle grinder and cut a hole big enough to put a long wire down the pipe and pulled out all kinds of terrible smelling soy beans or corn or who knows what.

Car drove 1000x better and just a few bucks to have the shop weld up the hole!
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Report this Post12-21-2014 01:24 PM Click Here to See the Profile for project34Send a Private Message to project34Edit/Delete MessageReply w/QuoteDirect Link to This Post
If your Fiero's catalytic converter is failing, you'll know it soon enough, perhaps even without any further testing of that hypothesis on your part.

More specifically, it's not atypical for that problem to manifest itself by limiting your Fiero's top speed more and more noticeably over time. For example, when my owned-since-new 1986 Fiero eventually first exhibited a catalytic converter problem, the car's top speed became lower and lower, eventually dropping to a mere 35 MPH --- an unsafe condition that I don't ever again want to experience on a freeway.


The other bad news is that a problem like that typically doesn't magically somehow just go away on its own: In my case, it simply became more and more noticeable until I replaced the cat.


If the problem is in fact a bad catalytic converter, the good news is that after you replace the cat, hookdonspeed, the dejected feeling you presumably had when the car started to accelerate like a slug should go away quickly --- because after replacing the cat, then the car will run normally again (even though that may be very difficult for you to believe right now, but that is what happened with my Fiero).
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hookdonspeed
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Report this Post12-21-2014 02:15 PM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
It will be replaced with a price of pipe soon as I can talk myself into going into the cold.
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Report this Post12-22-2014 08:04 AM Click Here to See the Profile for FIEROPHREKSend a Private Message to FIEROPHREKEdit/Delete MessageReply w/QuoteDirect Link to This Post
Check your injector fuses. I had one just pop on me one day as i was driving home from work. Engine lost lots of power couldn't get over like 40 MPH. I though I had a really big issue but found the inj 1 fuse blown. Replaced it and viola back to normal! I have had a cat clog on me before also but it didn't come on out of nowhere. It was a gradual thing over several days.

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hookdonspeed
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Report this Post12-22-2014 10:56 AM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by FIEROPHREK:

Check your injector fuses. I had one just pop on me one day as i was driving home from work. Engine lost lots of power couldn't get over like 40 MPH. I though I had a really big issue but found the inj 1 fuse blown. Replaced it and viola back to normal! I have had a cat clog on me before also but it didn't come on out of nowhere. It was a gradual thing over several days.



not the issue, else pulling the O2 wouldn't have fixed that... lol
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Report this Post12-22-2014 12:46 PM Click Here to See the Profile for steve308Send a Private Message to steve308Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hooked --- I had a similar problem two years ago. On the way to Carlisle my car began to lose power especially on uphill grades. Made it to the show but on the way home it got progressively worse and it could barely climb the mountain on the way home but it did make it. A couple of days later I put it up on stands and as the cat heat shield was shot I did a "hammer" check on the cat. I could hear the chunks rattle around when I tapped (hit) the cat and when I started it up a lot of honeycomb clag blew out the tail pipe and the power was back. PS - Not going to get into the pro's and cons of replacing the cat, using a resonator or a straight pipe in it's place . That's been argued to death here.

[This message has been edited by steve308 (edited 12-22-2014).]

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Report this Post12-22-2014 12:50 PM Click Here to See the Profile for FIEROPHREKSend a Private Message to FIEROPHREKEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by hookdonspeed:


not the issue, else pulling the O2 wouldn't have fixed that... lol


True true! Is your cat the original pellet style or a new honeycomb/monilith style?

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ARCHIES JUNK IS FASTER THAN SHAUNNA'S JUNK

12.3 is faster than a 13.2

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hookdonspeed
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Report this Post12-22-2014 12:54 PM Click Here to See the Profile for hookdonspeedClick Here to visit hookdonspeed's HomePageClick Here to Email hookdonspeedSend a Private Message to hookdonspeedEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
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Originally posted by steve308:

Hooked --- I had a similar problem two years ago. On the way to Carlisle my car began to lose power especially on uphill grades. Made it to the show but on the way home it got progressively worse and it could barely climb the mountain on the way home but it did make it. A couple of days later I put it up on stands and as the cat heat shield was shot I did a "hammer" check on the cat. I could hear the chunks rattle around when I tapped (hit) the cat and when I started it up a lot of honeycomb clag blew out the tail pipe and the power was back. PS - Not going to get into the pro's and cons of replacing the cat, using a resonator or a straight pipe in it's place . That's been argued to death here.



lol, I know.. I have a 3.4TDC sitting waiting for the weather to break, so I cant see spending the $ on a cat when its gona be pulled back off in like 2-3 months for a new exhaust system anyway..
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