priyarae

HELP!!!! I have a 01 ml320 check engine light came on. It spit out fuel trim bank 1 & 2 code. The car ran fine until i replaced the Mass airflow meter. It instantly started hesitating, it lost power. The problems got better after being driven for 10 to 15 minutes. I was told i got a junk part soooo....... I bought another MAF. The car ran fine for 20+ miles. I shut it off engine light came back on and i had a hard time getting it to stay running. But once i drove it was fine. After being started a few more times it seems to be getting worse with each start. Last start i had to give it gas to keep it from dying

benzeboy

Have you cleaned or replaced the air filteralso clean the connector to the MAS.

blair_mbz

When you replace parts like that, make sure you CLEAR the stored fault codes in your DME. Just because you don't have a check engine light doesn't mean there aren't any stored codes still that may be causing problems. Also, there is some adaptation that needs to take place with the ECU, so if you change MAF's it may take a few miles for your car to adapt properly. You may have misfire codes.

Also check your ignition components: plugs and plug wires.

moxvicencio

I have the same problem but mine is just the fuel trim bank 2 (P0173). I was told to clean the MAF and change my air filter. Is this true or what could be the possible solution, please help. I also checked MAF sensor online on Amazon.com bosch around $140.00 & $70.00 after market including shipping fee, will the after market part works fine also??? thanks in advance...

Pancham

Hi,

First of all, it would help if you tell us the mileage of your trucks because some problems start coming out at certain mileage. Mine is a year 2000 ML320 and currently has 91,000+ miles and still runs great (knock on wood).

I think at 60k+ miles I also got the code P0173 when CEL came on. So being that it was already out of warranty, I tried to diagnose it myself. I bought an ODB sensor that can reset/clear the codes. I was also adviced to clean all parts leading to the MAF, change the air filter, and changed the MAF (I bought the Bosch brand... i think it is the same part being sold by MB only theirs is expensive). I also cleared the error codes when I replaced the MAF but the CEL still came back. I even changed the spark plugs and the oxygen sensors by the catalytic converter (oxygen sensor should be good for 100k)... and still the CEL came back on even driving it for awhile hoping that the new MAF will adapt. But no luck so I gave up, re-installed the old MAF and oxygen sensors; left the new spark plugs and air filter then went to my local MB stealership. They diagnosed it to be a faulty catalytic converter which was under warranty up to 100k. That's good!! now I have a spare MAF.

At 70k+ miles, the CEL came back again with the same P0173 code but I went to the stealership not because of the CEL but for warranty work based on a recall. Anyway, the stealership wanted $1,600 to fix the CEL but I asked which parts were faulty and the reason why it's so expensive. They started mentioning parts like MAF, spark plugs/wires, ignition coils, etc... I figured they're trying to do another number on me again. I learned my lesson when another stealerships changed all my brakepad/rotors at 24k while others on the forum said that rotors don't have to be changed at 24k especially if you don't drive hard. Anyway, I took back the truck and fixed it myself. It turns out that the MAF finally went bad and this is the first thing I did which was to replace the MAF. I inspected all the spark plugs and figured which once were dirty/black which could mean that it's not igniting well so the problem could be electrical. I bought 1 ignition coil (Bosch brand which is the same part the MB sells only theirs is expensive) just to diagnose which one is failing. Just imagine, the stealership want to replace all the coils and each one cost $100+ and there's 6 of them !!! I also bought a set of spark plug wire on ebay - Bosch brand meant for ML30 and with boots on - cost was $99 for set; stealership i think wanted $35 per wire... and there's 12 of them... yikes!!! So long story short, 2 wires were bad also... and the CEL light never came back. It is still good up to this day at 91k miles. In summary, the parts I replaced were MAF ($200+), 2 spark plug wires ($99 and still have 10 good spares), and throw in a new set of spark plugs ($70 - i could have used the old ones till 100K but this old truck deserves a new set... :-)). All ignition coils were good so now I have a spare ignition coil.

Now, since my truck is already old, I try to diagnose it first before going to the stealership. I've already changed the front and rear brakes then next time include the rotors. I also changed the driver side door lock assembly to fix the "machine gun problem" when locking the doors (all locks would come up then down then up again). I did the same fix on my 2004 C320.

I hope my experience helps. Good luck.

moxvicencio

Hey Pancham,

Thanks for your help.. learned a lot... Mine is a ML 320 2000 model with 78k miles... I tried cleaning it and replace the airfilter, but after a while check engine light is back again... I thinking of changing the MAF sensor, I want to try replace it with the aftermarket sensor, do you know if it will work??? if not guess don't have a choice but to buy the Bosch part.... I know, definitely I can't afford to have it fix in the dealership (stealership)


thanks again... cheers!!!

Pancham

Hi,

I will stick to Bosch if I were you. I believe that most of the parts in that engine is made by Bosch for MB. I think even the engine block is by Bosch. Here's a link to a part in ebay
http://cgi.ebay.com/ebaymotors/Merce...ht_2956wt_1165

Now that includes the housing. You can also buy the MAF without the housing for $120. I think I found my spare at Amazon.

Did you try to go underneath the truck and figure if the catalytic converter has a crack? Please read my first experience at 60K miles. You'll always get that CEL if the cat is broken and it doesn't matter which other parts you change. If I were you, I'd take it to the stealers and feed them the information that it might be the cat so they can check it first. It's under warranty up to 100K miles (or under 10years -- not certain about this, you have to check the emission warranty book). If the cat is fine, then take your keys and run as fast as you can!!! LOL... Seriously, I bet you they'll try to change every part they can to save time from diagnosing the real problem. In fact, I wont be surprised if they sell you a new engine!!

You've got all the info I outlined in my other post. Good luck and let us know what you find.

moxvicencio

Hey to all,

I got my new MAF sensor from Amazon for 140.00 including shipping fee. Installed it for a week now and drove it around 2xx miles already so far no check engine light.
The MAF I got is a BOSCH part also with housing and is easy to install. I also changed my air filter.
Total spent:
MAF - 140.00
Airfilter - 21.99 + tax
Equals = hopefully solve the problem

Thanks to all.... Cheers!!