OBD2 M104 Mass airflow sensor WORKS on OBD1!!!

[omeyhomey]

hey guys,

My MAS has been acting up i feel so i did an expirament today to see if a OBD2 MAS would work on OBD1 Jetronic system. well I installed the MAS today and it actually works i was impressed. The plug style is the same however my concern is the OBD2 is missing pin #3 on the MAS and only has pins 1,2,4,5 where as the OBD1 has all 5 pins. Does anyone know if this will cause a conflinct? The car did feel different but not necessarily better or worse... just different. Im hesitant to leave it plugged in for long period of time b/c i dont know if it will cause damage over long term to the stock electronics. Does anyone know what pin #3 does on the OBD1 MAS? I did like the fit and function of the OBD2 MAS though, takes up much less room, fits better with rest of intake and etc. anyways if anyone could help i'd appreciate it.

[jnenad16]

first, your car doesnt have a jetronic system( unless you retrofitted it to CIS), its HFM without ignition control.
second, Im a bit confused with MAS you have and the one you installed. As far as I know, they are the same. a missing pin shouldnt be of any significance if the car idles and revs fine.

nenad

[OzC36]

Hi Omeyhomey,

This sounds interesting. What MAS Part Numbers are the stock one and the test one?

My 1996 C36 MAS has Part Numbers:

Mercedes 000 094 05 48
Bosch 0 280 217 500

[omeyhomey]

Originally posted by OzC36
Hi Omeyhomey,

This sounds interesting. What MAS Part Numbers are the stock one and the test one?

My 1996 C36 MAS has Part Numbers:

Mercedes 000 094 05 48
Bosch 0 280 217 500

thats the exact MAS i got. Mine is a 96 C36 Mass airflow sensor. i upgraded to the new style.

Nenad - are you SURE that 5th pin does not matter? b/c the car ran fine and actually revved smoother, the car felt smoother but not necessarily more power at least not on the butt dyno. So should i reset/powerdown ECU and have it relearn the A/Fs? I hear that helps the car relearn new air fuel ratios when u make an adjustment. I'm also gonna try some toulene once the gas tank gets less than 1/2 tank to really test to see if the lean, dry, thin air up here at 3000feet + 91 octane gas is really working a number on the car.

[jnenad16]

I dont really know what would the extra pin be for. my guess its timing control, but I doubt it. even if it was, your ignition module is separate from your ecu.

as for toulene, Id suggest you try a better octane booster, like dynotab. toulene is good at boosting octanes, but its very corrosive and can burn up just about every part it comes in contact with.

nenad

[OzC36]

omeyhomey,

When you say upgraded to the new style OBD2 MAS, are you saying that is a Mecedes recommended replacement part number or that you found that it works by trial and error?

Also what is the Part Number of the new style OBD2 MAS please?

jnenad16,

Thank you for your comments and the heads-up warning on using Toulene.

[omeyhomey]

Originally posted by OzC36
omeyhomey,

When you say upgraded to the new style OBD2 MAS, are you saying that is a Mecedes recommended replacement part number or that you found that it works by trial and error?

Also what is the Part Number of the new style OBD2 MAS please?

jnenad16,

Thank you for your comments and the heads-up warning on using Toulene.

naw just pure trial and error, i think the proper upgraded part number was 000 094 006 ___ .

something like that. anyways the car does feel differnet without the 5th pin but i still cannot figure it out.


Nenad - toulene comes in the very gas you put in your car from the pump. Refineries really only make 1 type of gass (87-89 octane) and the add xylene or toulene to the gas so its already in the gas u have an is completely safe as long as the total percentage is between 30-40% of the total gas amount. F1 uses 90-95% toulene and 5% filler material (by regulations). so it is safe if you use it properly and it is the best octane booster. Also you can buy it by the gallon (roughly $13). Touelen is 114 octane lead free race gas, Xylene is 117 octane but personally i like toulene much better than xylene from personal use. anyways hope that helps

[omeyhomey]

Hey guys, just installed the new M104 MAS sensor. Today was the first time I used the new style MAS sensor AFTER the crankcase vent bypass mod and i have to say I am MUCH happier with the results. power is VERY smooth and the knocking/pinging is almost completely gone and the car is alot more responsive in the mid range, its still not perfect but I have a feeling the ECU just needs to adapt fora week or two. ttyl