Do MAF's have to be coded.

G-a-r-y

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Daft question I know, does a MAF need coding. Euro have a good discount at the moment so I bought a new one for £151. E320cdi 2004.
 

_Taz_

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nope straight swap....

however I am just wondering if the adaptations need resetting...

same as if you've changed an air filter ?

I remember doing this once I replaced my crapped out old air filters.
 

Carl@MBS

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2004 320cdi maf?? they are cheaper than that from mb for the 320cdi straight 6! its only a cartridge you replace and one from euro's is only fit for the bin.......


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turbopete

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on the subject of MAF's I looked at mine when I did the EGR mod. now ive found a similar looking 'sensor' in the plastic solid boost pipe, between the 2 rubber boost hoses that are between the intercooler and the inlet manifold. can anyone shed any light on what it does?
 

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If anyone needs maf for an I6, let me know as I have a perfectly good one in my toolbox gathering dust.
 

Uncle Benz

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on the subject of MAF's I looked at mine when I did the EGR mod. now ive found a similar looking 'sensor' in the plastic solid boost pipe, between the 2 rubber boost hoses that are between the intercooler and the inlet manifold. can anyone shed any light on what it does?

MAP, pressure sensor. Measures the boost pressure in the pipe. Rarely fail, but I have replaced a couple. Also seen the wires broken at the plug a few times.
 

turbopete

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i wondered what it was for and thought something boost pressure related. What are the symptoms if they fail or wires break, as a matter of interest (and for future reference!)
 

television

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With the MAF it has quite a fair range to adjust, it is not the MAF that turns the engine lamp on, it is the 02 sensor. The 02 sensor is the part that does the adjusting of the mixture based on the information sent by the MAF.

Once the 02 sensor has shifted too far from its stored values and range the engine lamp will come on. In most cases after a hard drive with the new MAF fitted, the engine lamp will go out on its own, but not always.
 

turbopete

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With the MAF it has quite a fair range to adjust, it is not the MAF that turns the engine lamp on, it is the 02 sensor. The 02 sensor is the part that does the adjusting of the mixture based on the information sent by the MAF.

Once the 02 sensor has shifted too far from its stored values and range the engine lamp will come on. In most cases after a hard drive with the new MAF fitted, the engine lamp will go out on its own, but not always.

I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES
 

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I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES

I know nothing about diesels Pete, then what ever controls the mixture on a d, as the MAF's are different on a diesel then maybe it does control it directly, I just do not know. :D
 

turbopete

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i believe that on modern diesels, its controlled (via the ECU) by signals from the MAF, Boost Pressure Sensor, Throttle Position Sensor, air temp sensor, Coolant temp sensor and probably a few other sensors, but i think that covers the main ones!
 
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G-a-r-y

G-a-r-y

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  • Thread Starter
  • Thread starter
  • #14
2004 320cdi maf?? they are cheaper than that from mb for the 320cdi straight 6! its only a cartridge you replace and one from euro's is only fit for the bin.......


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I've just checked with Mercedes before posting, on the old W210 the MAF was the cheaper cartridge. On the later W211 it comes complete, with 7% discount and plus VAT £221.
The Euro ones are genuine Bosch, identical as used by Mercedes. 30% extra off £151.
 

Uncle Benz

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I could be wrong on this Malcolm, but as the OP's car is a DIESEL, im not sure the O2 sensor is even fitted! I certainly dont have one on my diesel, and off the top of my head, i cant think of a diesel that DOES

Would you care to have a little wager on that??
 

ThinkPad

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My diesel 320 cdi definitely has an o2 sensor.

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AdamG

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Gary, if you're think your maf sensor is not working check the wiring to the plug. On my w220 with the same engine the harness was cable tied to the plug as a strain relief. Unfortunately this doubling back setup kinked and fatigued the wires.

On the star test mine would not be in the green zone until I fixed the harness. It was only after I bought a new maf that I discovered it though:Oops:

Strangely I did not notice any difference before or after:confused:

Adam
 

turbopete

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Would you care to have a little wager on that??

which part? i am positive i cant think of a car ive worked on that has an O2 (lambda) sensor on the exhaust, and unless its attached to either the exhaust manifold or the turbo itself, ive had the ENTIRE exhaust off my car at some point or other so i can be 110% sure its not in the rest of the system!

whether later cars have them though, I cant be certain. like yourself, I can only draw on my own experiences to try to help people out with problems.

the fact ive never seen an O2 sensor on a diesel is the main reason why ive never been able to see the point in a diesel having CAT's etc!
 

Miffy

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which part? i am positive i cant think of a car ive worked on that has an O2 (lambda) sensor on the exhaust, and unless its attached to either the exhaust manifold or the turbo itself, ive had the ENTIRE exhaust off my car at some point or other so i can be 110% sure its not in the rest of the system!

whether later cars have them though, I cant be certain. like yourself, I can only draw on my own experiences to try to help people out with problems.

the fact ive never seen an O2 sensor on a diesel is the main reason why ive never been able to see the point in a diesel having CAT's etc!

http://forums.mercedesclub.org.uk/showthread.php?t=72738
 

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