E-Class (W210) 1995-2002: E 200, E 220D, E 240, E 290TD, E 300TD, E 200, E 240, E 280, E 320, E 420, E 430 (Wagon, Touring, 4Matic)

Questions regarding catalytic converters on an E240

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Old Jan 10, 2012 | 04:32 AM
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1999 E240 Elegance
Questions regarding catalytic converters on an E240

1: what is the expected life-span of the cats?
2: How do you tell if they're finished?
3: Can you remove them, without negatively influencing the motor?
4: and if so, will the removal result in any performance/fuel consumption improvement?
FYI: Fortunately, they're not so strict on emmision regulations in South Africa yet, and I cannot afford to replace the cats at the moment.
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Old Jan 11, 2012 | 12:09 AM
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Originally Posted by SoutieRSA
1: what is the expected life-span of the cats?
2: How do you tell if they're finished?
3: Can you remove them, without negatively influencing the motor?
4: and if so, will the removal result in any performance/fuel consumption improvement?
FYI: Fortunately, they're not so strict on emmision regulations in South Africa yet, and I cannot afford to replace the cats at the moment.
1. it varies
2. take a rubber mallet and hit the cat housing and see if it rattles.
3. yes
4. probably not if you just gutted them, maybe a very small amount of power if you got a straight pipe welded in its place.
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Old Jan 11, 2012 | 01:17 AM
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1999 E240 Elegance
Hi, Thank you for the reply, I suspected as much.
Next question, which of the O2 sensors do I need to worry about if I remove the cats? As far as I know there are o2 sensors before the cats, on the exhaust manifold, and another set after the cats, but I'm speaking under correction. Can the "post-cat" o2 sensors be ignored/bridged?
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Old Jan 11, 2012 | 01:21 AM
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
3. NO

If you remove the primary cats you will have issues.In order to do a primary removal you need to create a false signal otherwise the o2 sensors will throw a cel,run rich all the time,and other not fun results.
Remove the secondaries and you gain some sound but not any noticeable power.
A good cat on a well maintained engine can last the life of the car. A defective cat can go anytime,a poorly maintained engine can kill a cat in a matter of days.
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Old Jan 11, 2012 | 01:30 AM
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1999 E240 Elegance
Hi,
Well, that is part of my concern, since I've got a MAF that's playing up, and struggling to source an affordable part here in RSA, and it's just a question of time before the 'dodgy' fueling creates havoc with the cats, so I'm trying to be a little pro-active. I know it's side-stepping the real problem, but I'm trying to work around it.
A MAF here, as quoted by the dealer is R4700 (approx $600), which I feel is excessive, and am investigating overseas options, but I'm concerned that the cats have taken a knock already.
How would I go about creating that "false signal"? I am reasonably handy with a soldering-iron, and have strong electronics basics. I assume the 'computer' is expecting a varying signal from the sensor, however, if the sensor is bridged with a resistor to simulate a middle of the range signal, the 'computer' will be reasonably happy with that. Correct/incorrect?
I appreciate the input/answers thus far, thank you.
On a second point, anyone out there prepared to assist me in sourcing a new MAF?
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