catalyic convertor and a 4.7 200

[GX-R]

hey guys

i removed the catalyic convertor in my 200

it sounds better ( but smells < no problem with that )

anyway, im worried about a couple of things now beside it not passing the emissiont test!


will the torque go down ? because i herd it would show a difference in old cars just not new cars because they are programed to run with catalyic convertor and that their is a danger of the car to leak unburnt fuel from the exhaust and catch fire is that true?
thanks

 

[007-FJC]

Old carbureted cars dumped fuel into the engine VS EFI which injects a precise amount of fuel into the engine for enhanced performance and fuel economy. A catalytic converter's job has nothing to do with the fuel. EGR's recirculate unburned gasses back into the intake manifold to be burned. A catalytic converter reduces the toxic fumes which is the crap you smell. It does nothing for performance except it'll kill your performance if it happens to melt and slow the flow of your exhaust. Thats very unlikely to happen any time soon. And in most cases, cats that do melt usually spit chunks out of the tailpipe.. sometimes.

What you just did is your giving the person cruising behind you in the highway a big headache because he has to smell your toxic fumes.

 

[sand drifter]

FYI- I have the Baja Lexus 200 LX570 and I went back and fourth with Toyota engineers about cats and racing. I finally removed them and kept the front 02 sensors in and removed the rear. The truck feels noticably faster and sounds way better ( 2 shorty magnaflows) runs really well. Anyway, I don't need to worry about emissions but I thought I would at least share with you.

 

[007-FJC]

Yeah, but the Baja Lex is a race truck where this guy is driving a car in highways. Following a car with no cats is like following an old 60s era vehicle. You smell all the toxic fumes that the cat helps eliminate. There's other ways to increase the performance of a daily driver without killing the cats. Headers are a good way and for sound, flowmasters and V8s go in harmony beautifully.

 

[JBHorne]

There are actually four cats on the 5.7 200's (not sure about the 4.7). There are two in front of the rear O2 sensor and two behind the rear O2 sensor on separate Y pipes from the exhaust manifolds.

If you remove both the front cats, your computer will spit codes due to the placement of the O2 sensors. If you remove the two rear cats you should not have any computer problems as these are after the O2 readings.

So did you remove all four or just the rear two???

I was thinking about cutting out the rear ones, but I don't see the point as this will possibly fail emissions. I have thought about upgrading all 4 to high-flow cats, but this is $$$ for the seemingly minor power gain.