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You can do a soft reset for free..

It seems to me, that once a week you can do a "soft reset" which takes less than 3 minutes, effectively the simplest and free method to keep your "zoom" factory settings.

I don't know of a way to overrid/cancel the adaption feature myself.

Keep the beat !
 

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It seems to me, that once a week you can do a "soft reset" which takes less than 3 minutes, effectively the simplest and free method to keep your "zoom" factory settings.

I don't know of a way to overrid/cancel the adaption feature myself.

Keep the beat !
I know of a way to completely get rid of the adaptation on the ecu, by unplugging electrical connectors to front 2 o2 sensors car will run constantly in open loop mode, the mechanic told me it is safe to do but this will be my last resort option if I can not figure out another way to fix the power loss.
 

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I know of a way to completely get rid of the adaptation on the ecu, by unplugging electrical connectors to front 2 o2 sensors car will run constantly in open loop mode, the mechanic told me it is safe to do but this will be my last resort option if I can not figure out another way to fix the power loss.
A Technician will tell you that running your car in open loop will destroy your catalyst. But I'm sure your super duper Master Mechanic knows better.
 

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A Technician will tell you that running your car in open loop will destroy your catalyst. But I'm sure your super duper Master Mechanic knows better.
he did mention that it could be bad for cats if ran like that for long periods of time but i only have 2 cats upfront
 

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I changed my O2 sensor almost 3 weeks ago. It seems to stop the sputtering once I start it first thing. My problem is it comes and goes but what really noticeable is going up hill it has a hard time. If you put your foot half way on the accelerator you can feel it pick up but with a full pedal on the gas it seems to slow it down. How do you reset your computer in your car? I think it might be the fuel filter. What do you think guys? My engine light hasn't come on yet. That's what my mechanic told me to look out for.
 

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I changed my O2 sensor almost 3 weeks ago. It seems to stop the sputtering once I start it first thing. My problem is it comes and goes but what really noticeable is going up hill it has a hard time. If you put your foot half way on the accelerator you can feel it pick up but with a full pedal on the gas it seems to slow it down. How do you reset your computer in your car? I think it might be the fuel filter. What do you think guys? My engine light hasn't come on yet. That's what my mechanic told me to look out for.
try a hard reset by disconnecting the battery under the seat for 2 minutes and report back with the results
 

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Sometimes advice can be misleading..

Running "open loop" is not the solution to "performance" - and will just lead to premature failure of the cat's.

The O2 sensors have way-way less importance (if they are not throwing codes) than a MAF. The tolerance on the MAF can go way off, before throwing a code, and that variance can affect "performance" way-way more than a O2 sensor that has wandered from spec (again, that has not yet thrown a O2 sensor code).

1) Do a forum search - a proper "hard reset" WITH KEY OUT OF IGNITION disconnect both battery cables from the battery - touch trhe ends of the cables together, I twist tie them together for like 1 min, then reconnect the cables to the battery, and then WAIT for about 10 minuted BEFORE you put the key back in the ignition.
If you disconnect the battery for 2 minutes, without lopping out the system with the cable end connect, then the ONLY thing you are doing over a "soft reset" is killing the accessory system codes (like radio, windows, etc).
Make sure you follow ALL the system reset procedures outlined in the actual owner's manual.

2) If you easily want to maximize your existing perfomance - do a "soft reset" - which resets the major systems, but does not zero out the acceossry systems. After the soft reset, no additional reprogramming of accessory systems is required.
If the car has been not reset in 2-3 weeks, then if a "softie" doesn't immediately perk up the zoom-zoom, then start looking for other symptoms.

I have seen more (a) no softie reset (b) aged/out of spec MAF, and (c) dirty air filters do more to screw up E55 "performance" way-way-way more than failure of specific mechanical components.

If you are not happy, then the cars is worth the chase.
 

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Running "open loop" is not the solution to "performance" - and will just lead to premature failure of the cat's.

The O2 sensors have way-way less importance (if they are not throwing codes) than a MAF. The tolerance on the MAF can go way off, before throwing a code, and that variance can affect "performance" way-way more than a O2 sensor that has wandered from spec (again, that has not yet thrown a O2 sensor code).

1) Do a forum search - a proper "hard reset" WITH KEY OUT OF IGNITION disconnect both battery cables from the battery - touch trhe ends of the cables together, I twist tie them together for like 1 min, then reconnect the cables to the battery, and then WAIT for about 10 minuted BEFORE you put the key back in the ignition.
If you disconnect the battery for 2 minutes, without lopping out the system with the cable end connect, then the ONLY thing you are doing over a "soft reset" is killing the accessory system codes (like radio, windows, etc).
Make sure you follow ALL the system reset procedures outlined in the actual owner's manual.

2) If you easily want to maximize your existing perfomance - do a "soft reset" - which resets the major systems, but does not zero out the acceossry systems. After the soft reset, no additional reprogramming of accessory systems is required.
If the car has been not reset in 2-3 weeks, then if a "softie" doesn't immediately perk up the zoom-zoom, then start looking for other symptoms.

I have seen more (a) no softie reset (b) aged/out of spec MAF, and (c) dirty air filters do more to screw up E55 "performance" way-way-way more than failure of specific mechanical components.

If you are not happy, then the cars is worth the chase.
I have changed 2 MAFs in last 6 month 3rd one is one the way (cause all the symptoms lead back to faulty MAF), changed spark plug 2 times, spark plug wires, new 02 sensors. Still no fix yet to loss of performance plus i have a rough idle which cant be diagnosed either, no codes on the car at all.
I realize that 02s are less important than MAF for performance but the point is to put the car in the open loop to disable Long Term fuel trim where my problem lays. Long fuel trim in the open loop under wot goes to -15% which is what is killing performance on my car at least.
 

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Maybe bad parts...

A genuine Bosch MAF sensor, are getting easier to get knockoff parts, I hope you bought the sensor w/hosuing from someone reputable (oft mentioned autohausaz.com for one). That should solve the problem, if somehting else has been too gimmicked out.

The OE sparkplug replacements (which are actually a upgrade from the original design are just fine, anything else is overkill and/or not a add-on in performance.

The only case I have seen that required a full spark plug wiring replacement was a guy who fired his engine on a overheating issue (the kook had put his fans on "manual" or so he thought).

If you are running CarSoft, don't get overkilled by data and tweak, the factory defualts (if you have not lost them) are agressive.

It is not worth the chance to ruin your front cats forever running in open loop - at best case to get the car to the shop maybe, but running around down on a daily basis will lead to a very rude bill.

You haven't mentioned your airbox, the stock filters do fine - a oiled filter can ruin a MAF in our big V8 sucking all that air in about 50-100 miles - sucks shit right dwon the throat.

"Rough" idle could be a bad mount, if it is not a traceable misifiring plug - I assume you used dialectic grease when you replaced the plugs a 2nd time, right ?
 

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A genuine Bosch MAF sensor, are getting easier to get knockoff parts, I hope you bought the sensor w/hosuing from someone reputable (oft mentioned autohausaz.com for one). That should solve the problem, if somehting else has been too gimmicked out.

The OE sparkplug replacements (which are actually a upgrade from the original design are just fine, anything else is overkill and/or not a add-on in performance.

The only case I have seen that required a full spark plug wiring replacement was a guy who fired his engine on a overheating issue (the kook had put his fans on "manual" or so he thought).

If you are running CarSoft, don't get overkilled by data and tweak, the factory defualts (if you have not lost them) are agressive.

It is not worth the chance to ruin your front cats forever running in open loop - at best case to get the car to the shop maybe, but running around down on a daily basis will lead to a very rude bill.

You haven't mentioned your airbox, the stock filters do fine - a oiled filter can ruin a MAF in our big V8 sucking all that air in about 50-100 miles - sucks shit right dwon the throat.

"Rough" idle could be a bad mount, if it is not a traceable misifiring plug - I assume you used dialectic grease when you replaced the plugs a 2nd time, right ?
MAF I bought were form AZautohouse OE "Bosch" mentioned above.
my plug wires came greased from factory which was nice. I can not trace the misfire at all...
Airbox is stock with OEM type paper filters , I do not feel safe using K N types cause of reduced filtering ability.
 

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You might have a bad cat holding you back..

You might have a bad cat holding you back, if everything else get's swapped out..
 

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You have mentioned a -100bhp reduction in power, that kindof power loos can only come as a result of serious restriction in-or-out.

Normally, a soft reset restores the factory defaults, and then the factory defaults degrade over drive time, but 4-6 weeks is not uncommon before even a hep owner "feels" the need to do another soft reset to get the zip back.

However, degrading the factory defaults that result in a - 100bhp loss, something has to be very wrong - wouldn't be the fuel supply, or the soft reset wouldn't improve fuel pressure loss, the only thing it possibly could be in my mind is a major cat problem - if the soft reset restores the defaults, then the resstrictive cat cause the 02 sensors to lean everything back down (and fast).

I have not had any cat problems whatsoever, so I am not hep on that backend issue - but yes, could be the cause of the major performance loss you describe.
 

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You have mentioned a -100bhp reduction in power, that kindof power loos can only come as a result of serious restriction in-or-out.

Normally, a soft reset restores the factory defaults, and then the factory defaults degrade over drive time, but 4-6 weeks is not uncommon before even a hep owner "feels" the need to do another soft reset to get the zip back.

However, degrading the factory defaults that result in a - 100bhp loss, something has to be very wrong - wouldn't be the fuel supply, or the soft reset wouldn't improve fuel pressure loss, the only thing it possibly could be in my mind is a major cat problem - if the soft reset restores the defaults, then the resstrictive cat cause the 02 sensors to lean everything back down (and fast).

I have not had any cat problems whatsoever, so I am not hep on that backend issue - but yes, could be the cause of the major performance loss you describe.
Well my thinking is that if the cats were clogged: restriction after a reset would no go away so power loss would be immediate not gradual
 

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i have the same problem. sometimes the car gives really powerful acceleration but sometimes it's not that much powerful. what is the actual problem?
 

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Hi guys,

Same sort of issues. I’ve taken a video of before and after my hard reset to show the difference in acceleration but I don’t know how to post them here.

Would appreciate any advice as well thanks.

Steven
 

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Just a consideration, but is it possible you have a EVAP/vacuum leak? Have you had a smoke leak test performed?

I ask this because I purchased a new to me 2000 E55 last summer. The car kept on having CEL codes P0170 and P0173. I replaced many, many parts. MAF, spark plugs, breather hoses, vacuum lines, gasket between throttle body and intake manifold, O2 sensors. After all those parts and still getting codes, I took it to a great mechanic with a smoke leak test machine. He hooked it up and you could see faint smoke coming out of the sides of the engine as he pumped smoke into the intake from the MAF. The problem was the gaskets between the intake manifold and the heads were leaking. Replaced the gaskets and no more engine codes. The car ran much better because it could control the fuel trim within parameters.

I don't feel the parts a replaced were a complete waste. I didn't know the history of the car so I consider it maintenance :)

Best of luck with solving your issue.
 

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Hi Fellas, Razor1, Stevenkrash, Fotoflame,

You do realize the last active post was over 9 years ago.....
Best for you to start a new thread and refer to this old one.
As well, post in the w210 thread may get you a faster response.
 
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