catalytic converter plugged?!?!?!

[itsaboattime]

I know we have some ASE mechanics out there. My 1995 F150 with a 300 inline 6 cyl. is having power issues. It has been loosing power little by little for a while now and just recently is doesn't wanna run or move at all!! I got it to idle the other day. After about 10 mins at idle, I smelled somthing really hot so I checked under the hood and the exhaust pipes between the exhaust manifold and the catalytic converter were glowing red hot!! So I shut it down and have been looking for answers since.

I believe the converter is plugged. The more I think about it, the more it adds up. If anybody has any input I would appreciate it.

At one time you could eliminate the converter from the exhaust completely, but I think if I try it with this truck it'll screw up the computer......Am I right on that??

 

[a70eliminator]

Re: catalytic converter plugged?!?!?!

Cant screw it much more than it is now, I've heard of plugged converters starting fires but I myself have never experienced a plugged cat on any car or truck I've owned.
I do know that too much timing advance will glow red hot exhaust pipes and melt pistons. If the cat is plugged up that bad you should be able tell at the tailpipe just by listening and observeing how much exhaust is comming out. Throw a timing light on it and see where that is.

 

[DECK SWABBER 58]

Re: catalytic converter plugged?!?!?!

Too rich a fuel mixture will make the cat. conv. really work and get too hot.

What do you mean by gradually losing power? Is it misfiring, running
rough etc. ?
Easiest way to check if it's plugged is to disconnect exhaust pipe
at manifold and drive it.

Removing cat. conv. won't ruin computer. It might turn on check
engine light. If the conv. is the problem you can get a universal
installed pretty reasonably at an exhaust shop like Meineke.

Depending on where in Illinois you live if you have to pass an emission's
test you definitely don't want to remove it !!!

 

[4JawChuck]

Re: catalytic converter plugged?!?!?!

I have had two vehicles die because of a plugged converter, every time the converter would overheat the vehicle would lose power and in one case even stalled the motor when I lifted off the accelerator.

I would look after this ASAP since the last vehicle burnt the exhaust valves from the blockage, I found out the hard way staring under the hood of a stalled vehicle on the side of the highway with orange hot exhaust manifolds 100 miles in the middle of nowhere. I am not entirely sure if the exhaust valves leaking caused the converter damage or vise versa...it ran fine for the few weeks prior to the "dead on the highway" scenario.

Both vehicles were Chevy's with those dreaded pellet converters...they seem to be the worse although I had a Taurus SHO whose honeycomb converter collapsed, but the rattle gave it away when you stepped on it. That car never showed any signs of converter death but I just think I caught it in time.

 

[Bondo]

Re: catalytic converter plugged?!?!?!

I believe the converter is plugged. The more I think about it, the more it adds up. If anybody has any input I would appreciate it.

Ayuh,... Remove the O2 sensor from the pipe, Before the Cat...
If the Cat is plugged,...
It'll run just Fine, although Noisy...

If that's the case,.. Replace the Cat...

 

[itsaboattime]

Re: catalytic converter plugged?!?!?!

I mean that I have noticed a slow, steady, decline of power over the past year. It also seems to drink alot more gas per mile. No rough idle issues and it accelerated ok, just a lil "doggy". But it seemed that while pulling a load(boat, horse trailer) it took longer to get up to speed and more gas pedal to keep it there.

No emissions testing around here. We are out in the sticks, farm country is exempt from test lanes.

 

[joey maneri]

Re: catalytic converter plugged?!?!?!

Im pretty sure that on a 95 It does not have a o2 sensor after the cat(cat monitor) This o2 sensor only tells the computer if the cat is working, nothing else. You could hollow out the cat but you would fail the emisions test. not to sure if you have emision testing where you live. If you pull the front o2 sensor out like prev. stated, make sure there are no wirring or anything flamable in front of the open o2 sensor hole before you try to see if it runs better.

 

[MRS]

Re: catalytic converter plugged?!?!?!

If you have no smog test cut that thing off and see what it does. I had a 79 chevy 4x4 with 300,000 miles on it. Went to make a dump run and half way there it would only run about 10 mph if that fast turned around and headed home finally got home pulled it in the driveway and figured time to rebuilt the motor. Rebuilt the motor fired the motor up and same thing. I thought man it could only be the cat. so cut it off fired up and that was it. But with 300,000 on it it was due for a rebuilt drove it another 4yrs. and sold it....

 

[JustJason]

Re: catalytic converter plugged?!?!?!

They do make a backpressure gauge to test for clogged cats.

 

[ddrieck]

Re: catalytic converter plugged?!?!?!

Get one of those cheap vacume gauges and hook it to a vacum port on the exhaust manifold. Start your truck, look at the gauge, and slowly throttle it up. If the gauge starts to fall toward zero then there is somthing in the exhaust system that is clogged up. This could be the cat, muffler or pipe.

You mention your in farm country; Does your truck sit for any length of time in between uses? If so, mice may have built a nest in the muffler and the back pressure is causing your cat to overheat.

I have delt with several of these same situations over the years and most have been a nest in the muffler.

 

[kend301]

Re: catalytic converter plugged?!?!?!

Very easy way to tell if you have a clogged exhaust is to have a friend rev the motor up while you have your hand about 6 INCHES from the exhaust pipe , If there is no air flow and what does come out is hot as he11 you have an exhaust restriction . You can take out the O2 sensor before the cat conv to see if it runs better but you are better off getting under the vehicle with a rubber hammer when the vehicle is COLD and hit the converter and see if it rattles , If so it is junk .

 

[gss036]

Re: catalytic converter plugged?!?!?!

Fords do clog up. my son-in-law just had to replace his on late 90's 1/2 ton ford. Same thing , no power.

 

[alumi numb]

Re: catalytic converter plugged?!?!?!

Ayuh,... Remove the O2 sensor from the pipe, Before the Cat...
If the Cat is plugged,...
It'll run just Fine, although Noisy...

If that's the case,.. Replace the Cat...

that's good thinking.
i just went to the cat shell and cut out about a 3" sg.
there was a plug of the stuff that broke away in the pipe.
broke it up and the truck ran fine "dakota".
have a little miller cricket so easy to close the shell.
that welder is like a microwave, once you have one you can't live without it.
just what happened to me me, engine can't exhale.

 

[itsaboattime]

Re: catalytic converter plugged?!?!?!

Just an update..........gonna cut the two converters out tomorrow and just pipe it all back together.

The cat is toast. I did the pull the o2 sensor thing and the smack it with a mallet thing and the hot exhaust thing. They all point to a bad cat.

I'll let you all know what happens.

 

[Bob_VT]

Re: catalytic converter plugged?!?!?!

I have encountered the same problem before and it drove me nuts.

BEFORE you do any cutting please try this......

Put a timing light on the car and start it up. Watch the timing marks and have someone bring the rpms up. Is the timing advancing????

The problem I had with the same exact symptoms as you was caused by the ecu and ignition. The timing advance is electronic and I had some parts that went south and would not allow the engine to advance.

My cat (which I thought was clogged solid) was fine and it turned out to be an ignition module.

Please try the test since it is cheap, fast and easy.

 

[itsaboattime]

Re: catalytic converter plugged?!?!?!

Well........I got it finally!!!!

I checked the timing like Bob suggested above and it was advancing so I figured that wasn't the issue. So I then cut out the converters. A buddy and I then worked for about an hour to clear them out. We re-installed the now empty shells back into the exhaust and fired it up. It ran like crap. Called a couple of places and was told that now there is very little(by comparison) back pressure and the timing needed to be adjusted.

We then retimed the old girl and she is back on the road, with plent of power!! And as an added bonus lots better milage. No check engine light, and did I mention better milage??

Thanks guys.........

 

[Gary H NC]

Re: catalytic converter plugged?!?!?!

Glad its fixed! I gutted both of my cats and never had a problem.

We used to have a Pontiac Grand Am that needed the cat replaced about every 3 years...600 bucks!
Traded that POS....

 

[redfury]

Re: catalytic converter plugged?!?!?!

Glad its fixed! I gutted both of my cats and never had a problem.

We used to have a Pontiac Grand Am that needed the cat replaced about every 3 years...600 bucks!
Traded that POS....

If you are losing cats that fast, then there was probably another issue causing it. It's easy to figure out what the problem is and fix it....finding out WHY the problem happened is usually the harder and more important thing to figure out.