Symptoms of a bad catalytic converter?

[alan lx]

I had a 92 Nissan v6 that had was doing something similar. The cat would get so hot it would be turning red. So i had a bright idea of "gutting" the cat. After i gutted it, the cat stop turning red but it still had a terrible miss esp when hot. It got so bad it would actually shut off and wouldnt start til it cooled off. It turned out to be the crank sensor in the distributor. I know this sounds crazy but its a true story. The sensor would get hot and start messing up. After it cooled down it ran okay. True story.
I am trying to remember the inside of a cb distributor if it has a sensor like this or not.

[zedjr10]

Alright so i'm having some strange issues with my accord

Today i was driving it on the highway in heavy stop and go traffic. The car was having a hesitation every time i tried to move forward. I also started to get this very nasty unburnt fuel smell in the car. No i didn't get any CEL

So later after i got to where i was going it was happening again, i had the car idling while i was sitting inside talking with my boss who was outside the car. Immediately he notices the smell as well.

The hesitation and smell kind of come and go. The plugs, wires, distributor cap and rotor are all in good condition. The o2 sensor was replaced very recently when i changed out the down pipe. The car doesn't and has never had any CEL's since i've owned it.

I was thinking maybe the catalytic converter is clogged which would explain the loss of power but would it explain the small?

Also if i idle the car for over 5 minutes the temperature gauge goes up to about 3/4th's. It won't over heat but it will climb up to there.

The car also gets terrible gas mileage, i got 280 miles on this last tank of gas ( it was on E and i regularly fill up 13-15 gallons from that point.

So what was the issue. I have the same exact issue it seems. Come and go hesitation and i do smell some gas on occasion from my car. Plugs and everything on car is in good shape. Lots of work done recently but crappy gas mileage. I know this is old post but i also thought my cat might be partially clogged.

[Raf99]

Another simple test is to cover the exhaust pipe with your hand (wear a glove) and see if the engine dies out or if there is any exhaust coming out at all. Like shoving a potato in the pipe you should notice a big difference.

[zedjr10]

Another simple test is to cover the exhaust pipe with your hand (wear a glove) and see if the engine dies out or if there is any exhaust coming out at all. Like shoving a potato in the pipe you should notice a big difference.

Covered both tailpipes and engine idle stayed the same. I am assuming this means i got an exhaust leak after the cat or my exhaust would be louder but i shouldn't smell any raw gas then if that is true.Right? Also the smell of gas and rotten egg(most of the smell is raw gas) i get on occasion is coming from area of gas cap(rear drivers side). I banged on cat when cold and i hear nothing rattling in there at all. So what u think? Or anyone else?

[Fleetw00d]

Check the condition of the fuel lines on and from the tank; my tank was seeping around the level sensor gasket and even possibly through the rust on the tank itself. I had to replace my main fuel line a few years ago because it was so rusty that it was leaking.

[Raf99]

Covered both tailpipes and engine idle stayed the same. I am assuming this means i got an exhaust leak after the cat or my exhaust would be louder but i shouldn't smell any raw gas then if that is true.Right? Also the smell of gas and rotten egg(most of the smell is raw gas) i get on occasion is coming from area of gas cap(rear drivers side). I banged on cat when cold and i hear nothing rattling in there at all. So what u think? Or anyone else?

Do you have exhaust or pressure coming out the tail pipe. There should be some noticeable pressure here. Enough to move a pant leg if you stood by it, etc.

The other test I seen on youtube is take a heat laser finder gun ($20 cheap one will do). Measure the temps before the CAT and after. With the car warm you would see a high temp before the CAT and low temp after.

[zedjr10]

Check the condition of the fuel lines on and from the tank; my tank was seeping around the level sensor gasket and even possibly through the rust on the tank itself. I had to replace my main fuel line a few years ago because it was so rusty that it was leaking.

This is a good possibility given that the car runs very good for the most part except for mpg. One thing that bothers me is after cleaning egr system and replacing o2 sensor my gas mileage is same or worse. I am just thinking the best way to check all my fuel lines. Will have to go look at a fuel line schematic.

[zedjr10]

Do you have exhaust or pressure coming out the tail pipe. There should be some noticeable pressure here. Enough to move a pant leg if you stood by it, etc.

The other test I seen on youtube is take a heat laser finder gun ($20 cheap one will do). Measure the temps before the CAT and after. With the car warm you would see a high temp before the CAT and low temp after.

Yes there is noticeable pressure coming out the tail pipes. The problem with heat laser gun is that they only seem to measure up to 750 degrees f. I thought the cat gets up to 1200-1300 degrees farhenheit. Would this test be that conclusive i wonder. Am going to look for one to rent at parts store or get a exhaust pressure gauge and test it that way.