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1997 E420, 1990 560 SEL
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27 Posts
Discussion Starter #1
I have been chasing this ghost for months now. My 1997 E420 started with a hickup but then started to loose power. had my indy mechanic look at it and he noticed the pipe on the passanger side right infront of the cat was red hot. The exhaust smell is also very strong in raw fuel. He did a presure test at the exaust and said it was equil and didn't think the cat was cloged but to be sure we removed the front pasanger cat and found it clean as a wistle. So we replaced all 4 O2 sensors, all plugs, oil and filter change, and did a belt and water pump replacment as well at the same time. Care ran perfect for another 6k miles but then on a trip up hill I lost almost all power and got check engine light. I immediatly turned around and went home with no more problems but the light stayed on.
I have been ignoring the brake liner warning for a bit I know that rear needs a break job, can see where this comes into play but maybe.
I tried running the car and it idles fine but had less power, also the check enching light would blink at times telling me its having a missfire.
Checked the computer and had codes for the the front pasanger O2 sensor, missfore on cylinder 2,3,8 and a multiple misfires code.
The pipe also had started this red glow again and exhaust has a strong fuel smell. I replaced all plugs with no change, I replaced the 3 coils with no change. After that no it idles great but wont get above 2nd gear, I guess it is in the limp home mode now. I checked my codes again, after a reset all the same codes came back but now I have missfires reported in 1,2,3,5,8. I went ahead and replaced the MAF and still no change. Any ideas, other then towing it off to the dealer, with my wife out of work for a year those days of dealer repairs are out of the question for me and I hate seeing it just sit in the car port. :( Thank you for your time any any more suggestions.
 

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2001 E430 4matic
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419 Posts
For some unknown reasons to me everything pointing to cats and O2 sensors again! What type of O2 sensors you used? Was your MAF original (Bosch)? what is the mileage on the car? The problem is that you have misfire on the both banks and what ever the problem, is shared with the both banks. Smell of fuel pointing to O2 sensors ... red glow and lack of power to cats. MAF problem causing all the misfires, limp mode, lack of power and rich fuel again?

I recommend that you have your car scanned at the dealer for possible problems (probably $100) to troubleshoot. You don't need to have the repairs done there but at least you know instead of changing parts in random without being sure. I consider this option as more economic version of fixing your car.

Good luck.
 

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Registered
1997 E420, 1990 560 SEL
Joined
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27 Posts
Discussion Starter #3
For some unknown reasons to me everything pointing to cats and O2 sensors again! What type of O2 sensors you used? Was your MAF original (Bosch)? what is the mileage on the car? The problem is that you have misfire on the both banks and what ever the problem, is shared with the both banks. Smell of fuel pointing to O2 sensors ... red glow and lack of power to cats.
The first time I replaced them I used Bosh, I got some cheap generics on hand now for testing but have not tried them yet do to how hard it is to get at the one reporting bad.

I am told there is something called a "Test Pipe" which replaces the front cat with just a strait pipe and a port for the O2 sensor, Im guessing something like this would be great for seeing if the cat is an issue. Any ideas on that or experiance? Unfortunatly I can't afford new name brand cats for testing and all the good priced universal cats I have seen are to big for the space in the e-class.
 

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Premium Member
2001 E320 - Brilliant Silver/Ash: 107,000+
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17,193 Posts
Magnaflows should fit

...Unfortunatly I can't afford new name brand cats for testing and all the good priced universal cats I have seen are to big for the space in the e-class.
Not true. See the sticky about the aftermarket Magnaflow cats.
 

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Registered
1997 E420, 1990 560 SEL
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27 Posts
Discussion Starter #5
I will take a look I got a set of generics to test with but sent them back, they would have done fine for the rear cats but the front where I have the problem they where round not oblong and touched the pannels at spots. I'll see what I can find but if legal here I sure like the idea of remving the front cats all togeather.
 

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Registered
2001 E430 4matic
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419 Posts
Did you replace you MAF with a quality replacement (Bosch or original)? Since you have changed your MAF and all these symptoms you are having can also be as result of a failed MAF again minus the red glow cat.

As conclusion, I will closely check O2 sensors, Cats and failed MAF since you have to take into account multiple problems.
 
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