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Mike, UK Car Mechanic
Category: UK Car
Satisfied Customers: 39198
Experience:  Hi, I am a Car/ vehicle technician of 34 years. 29of -running my own repair/diagnostic business.
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1993 Land Cruiser: My Catalytic Convertor seems to stay hot

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My Catalytic Convertor seems to stay hot longer than the rest of the muffler. Some of the muffler guys I am talking to seem to think that this is a symptom of something that is wrong with it. Is this true?
Hello, I am Randall. I will do my best to answer your question
what do you mean by stays hot longer,. meaning after you trun engien off? has a temp reading been done?
Customer: replied 3 years ago.

Yes, after we turn of the engine. Temp reading has been done by the touch. Touch lower pipe on the muffler then touch the cat. Cat is much hotter. You also feel the heat coming of the Cat when wife is getting out of truck when I drop her at work. Is this a symptom of anything?

Is engein running ok? fuel miles etc all ok and what work has been done maintenance wise say in last year or so
Customer: replied 3 years ago.

Engine is running ok but i have been burning crazy gasoline. In fact that is why I was under truck. I was fixing leaks from exhaust manifold all the way through. Changed the 02 sensors. Tested most of the related sensors except for cooling temp sensor and one other. Checked air intake, Mass Air Flow and Throttle Pressure Sensors. TPS had to be adjusted and we did that. I was going to buy a pressure gauge today so that I can test the fuel pressure next. Fuel return worked ok when we tested it last weekend also.


I am getting 5mpg and I dont know why. Its killing my budget.

Tune up? last done?
Customer: replied 3 years ago.

In the last 3 months, i have new plugs, air filter, oil filter. Did some work on an oil leak and muffler when the gas mileage just shot up. Been trying to chase it down ever since. Im just going through the codes and suggested remedies.The 25 code has been persistent. Seems the 24 and 31 have not re-lit since fixing a leak in the pipe near the manifold.


I have not done injection work yet because it seems unlikely given how the car is running.

I did not know you had codes set. so 25 is still a current code?
Customer: replied 3 years ago.

Yes. Lean Fuel.

I am unsure, several different possibles. I would prefer to opt out and allow another expert to chime in on this one
One should be along shortly
Please do not respond to me as the post will remian locked to me. Thanks
Hello and Welcome back to justanswer..

The basic answer to your question as you asked at the outset is "yes"... the cat converter will stay hot a lot longer than any of the rest of the system -

To explain, while the rest of the system will get hot - because its metal and you get the normal heat transfer from the engine and the exhaust gases etc - the cat converter is designed to do its job at extremely high temps.

It is true to say as well though that if the engine is badly tuned or the valve timing for example is badly out - it will cause the cat converter to get hotter than it should - and that can damage the cat so that it doesn't function / do its job.

If you are genuinely concerned this may have happened or be happening, then the best thing to do is take the vehicle to a test station where they can do a exhaust gas test for you - simply to see if the cat converter is working as it should. If the readings are right for that vehicle ( they will have these) , then you know all is well - and its just normal heat output. If there is a fault, that will also tell you where to be looking on the engine / tuning etc.. so two birds killed with one stone as they say.

Let me now if you need anything else -

>> >> Meantime -- Please click on the OK rating to Excellent ratings service for me now, Thank you for that... and you can get back to me anytime if you need / wish..

Best Rgds, MIKE.

Please note, you are rating the content of my "answer" - my help to you - not the "system" which can experience delays etc which are not under my personal control -or delays caused by "time -off" which we all have on occasion - Thank you.

Mike, UK Car Mechanic
Category: UK Car
Satisfied Customers: 39198
Experience: Hi, I am a Car/ vehicle technician of 34 years. 29of -running my own repair/diagnostic business.
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