Gutted catalytic conv. question
#21
Originally Posted by Maddog
Tacoma dude >> Its sounds more likely that you cat is just cloged ,not gutted,
A gutted cat wont make your car go worse.there would be nothing stopping the air flow from gettting through if it was gutted,BackPressure is not an issue,Infact its a myth, But i dont have time to explain it.
Now that you have fixed the leak,all of the air is trying to go through the cat ,& for some reason the cat isnt letting it get through as well as it could.
That my 2 cents anyway
A gutted cat wont make your car go worse.there would be nothing stopping the air flow from gettting through if it was gutted,BackPressure is not an issue,Infact its a myth, But i dont have time to explain it.
Now that you have fixed the leak,all of the air is trying to go through the cat ,& for some reason the cat isnt letting it get through as well as it could.
That my 2 cents anyway
#22
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Maddog:
Actually, I have performance gain now that the leak is fixed. I'm feeling more power behind the pedal
I just never saw what this truck was like before the problems I had so I was just wondering if there was a surefire way to tell.
Actually, I have performance gain now that the leak is fixed. I'm feeling more power behind the pedal
I just never saw what this truck was like before the problems I had so I was just wondering if there was a surefire way to tell.
#23
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Originally Posted by CynicX
to keep its natural entropy....
Guys, backpressure is not a myth but it does depend greatly on the engine setup (HP or torque motor and normally aspirated or turbo/supercharger).
Last edited by MTL_4runner; 08-04-2004 at 01:17 PM.
#24
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So would a 2nd gen 4 runner gain or lose either hp or mpg by having the cat removed? or would it or would it not cause the o2 sensor to fail/cuase the check engine light to go on?
I know its an old topic but I was wondering.
I know its an old topic but I was wondering.
#25
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My experience with my 2nd gen - others mileage may vary. Mine runs a teenie bit better without the cat. It got 1-2 more mpg. It revs quicker (if you can use those terms re a 3.0) and feels noticeably more powerful between about 3000 and 4500 rpm. THese weren't HUGE differences, but they were noticeable. It sounds like crap however, the cat smooths out the exhaust note. The o2 sensor is before the cat, and has been unaffected. Been this way for 80,000 miles with no side effects. ON the other hand, the cat may not have been in prime condition before it was removed either. Hard to say if it's a performance benefit really. When I get around to doing something with headers and the exhaust, (or do an an engine swap) a cat is going back on there though.
Last edited by Flamedx4; 01-07-2005 at 08:45 AM.
#27
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iTrader: (3)
Not sure why you don't just remove the 2 bolts on one end of the cat and have a look inside. If the bolts are rusty, cut them off and replace with a couple of 3/8" s/s bolts and nuts. And if you find the cat is intact, you can also inspect the inlet end to see if it is clogged or not.
#28
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This is embarrassing, But ten years ago, I thought gutting the CAT on my '93 4x4 might help out. I ran it with a straight through pipe for a few years, blowing the factory and every other muffler within 10k miles, until it started failing emission tests. I had to replace the cat to pass, with a unit that was maybe a quarter of the size of the original. It was really a self inflicted wound. These Toyotas are very well tuned out of the box for all but competative performance levels.
#30
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Originally Posted by 4Crawler
Not sure why you don't just remove the 2 bolts on one end of the cat and have a look inside. If the bolts are rusty, cut them off and replace with a couple of 3/8" s/s bolts and nuts. And if you find the cat is intact, you can also inspect the inlet end to see if it is clogged or not.
It'll make header installation fun since I don't have a sawzall and I don't know how to weld
#31
i dont know what the problem is!
my name is andy and i also drive a 91 4runner... i have this question, when i acclerate there is a very loud ticking noise as if the exhaust was leaking. how can i figure out what the problem is. My mileage is also very bad! so if anyone has any ideas please let me know thx! andy
#33
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Originally Posted by nyceride
Mines ticking also....I think that is from the cat gaskets?? well I can feel air coming out from where the flanges are connected.
Andy,
Look around the exhaust manifold, under the heat shield on the exhaust manifold, the down pipe where the Y is welded, the gaskets where the manifold and Y pipe connect, and at the cat converter. These are all the places my truck has had leaks. Look for discoloration on the exhaust manifold (black or white streaks/ areas) I had a hairline crack in mine under the heatshield that was a pain to find.
Hope that helps guys.
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