How to Clean Mass Air Flow Sensor
Thread Starter
Newbie
Joined: Sep 2008
Posts: 1
Likes: 0
1998 ML320
How to Clean Mass Air Flow Sensor
My check engine light is on in my 1998 ML320.
As I understand it, the following codes
P0170 Fuel Trim Malfunction (bank 1)
P0173 Fuel Trim Malfunction (bank 2)
indicate a problem with the Mass Air Flow sensor.
I would like to try cleaning it.
Could I do it this way:
Open up the air cleaner.
Discard old air filter.
Clean out the interior with a wet cloth.
Start engine.
Spray Mass Air Flow Cleaner into air intake.
Install new air filter.
As I understand it, the following codes
P0170 Fuel Trim Malfunction (bank 1)
P0173 Fuel Trim Malfunction (bank 2)
indicate a problem with the Mass Air Flow sensor.
I would like to try cleaning it.
Could I do it this way:
Open up the air cleaner.
Discard old air filter.
Clean out the interior with a wet cloth.
Start engine.
Spray Mass Air Flow Cleaner into air intake.
Install new air filter.
Senior Member
Joined: Mar 2008
Posts: 289
Likes: 0
From: Queens, NYC
02 330i & 99 ML430
dont spray it into the filter area. do the following.
*be sure to clear codes that are stored
remove old air filter
clean area and intake box with wet rag then dry
install in new air filter
buy CRC Mass Air Filter Sensor Cleaner
loosen the MAF portion of the intake by loosening the screw holding the clamp
spray 15x on one side of the MAF
spray 15x on the other side of the MAF
be sure to hit the two wires that are visible in that area
use compressed air to dry the MAF
reinstall MAF portion of intake
put back intake box
start her up
*be sure to clear codes that are stored
remove old air filter
clean area and intake box with wet rag then dry
install in new air filter
buy CRC Mass Air Filter Sensor Cleaner
loosen the MAF portion of the intake by loosening the screw holding the clamp
spray 15x on one side of the MAF
spray 15x on the other side of the MAF
be sure to hit the two wires that are visible in that area
use compressed air to dry the MAF
reinstall MAF portion of intake
put back intake box
start her up
MBWorld Fanatic!
Joined: Nov 2001
Posts: 4,260
Likes: 6
From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
Keep in mind that cleaning is a band aid. MAFs are not made to be cleaned but are throw away when failed. Why not just replace it you will have to do that anyway. They are not expensive.
Super Member
Joined: Apr 2003
Posts: 690
Likes: 33
From: Bay area - California
2000 ML320 2006 SLK 350
The band aiding works well though...
Now, its throwing the check engine light every week after a clean up...that's the end of it.
http://www.germanstar.net/MAF.htm will sell you a MAF insert for $139....just go for it!
That's what I am doing....
Last edited by mihir_d; Sep 3, 2008 at 09:52 PM.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 4,260
Likes: 6
From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
The first time I had a MAF check engine light was at 66000 miles. I have since cleaned it thrice and gotten to 119000 miles on it.
Now, its throwing the check engine light every week after a clean up...that's the end of it.
http://www.germanstar.net/MAF.htm will sell you a MAF insert for $139....just go for it!
That's what I am doing....
Now, its throwing the check engine light every week after a clean up...that's the end of it.
http://www.germanstar.net/MAF.htm will sell you a MAF insert for $139....just go for it!
That's what I am doing....
Super Member
Joined: Apr 2003
Posts: 690
Likes: 33
From: Bay area - California
2000 ML320 2006 SLK 350
I am replacing my MAF this weekend...
What perhaps you do not realize is that the value that triggers the CEL is an absolute incorrect value for the vehicle. It does not mean that if the light is not on the values thrown off are within the best and correct operating range for the MAF. On an 02 ML500 that I had I noticed my fuel economy going south and the dealer changed the MAF even though I had no CEL and the fuel economy drastically improved immediately. As I said before cleaning is a Band Aid and the MAF's are throw aways. The operation of your engine I am certain was impaired to a certain extent by using the cleaned MAF.
I have been monitoring the mileage through my trip computer...and its about right for my 320....21 mpg on freeway, 18 in city...the torque & power hasn't felt much different from when it was new either.
I do however understand that a failing MAF will throw the ECU off in determining the correct fuel-air ratio...thereby directly impacting efficiency, power, torque and a lot more...
Early wear of the oxygen sensors, catalytic converters, spark plugs etc. A faulty MAF can indeed cause a lot of ill effects...
I have used my judgement & experience gained through changing other parts of the fuel burning system (spark plugs, cats & MAF cleanups) to determine, when was the right time to say goodbye to the MAF and replace it for good.
MBWorld Fanatic!
Joined: Jun 2003
Posts: 9,498
Likes: 4
From: San Diego, CA & San Jose, Costa Rica & Stuttgart, Germany
1959 220S / 1979 230 G / 2002 A210 AMG / 2003 C320 SC / 2004.5 C320 SS / 2005 ML350 SE / 2008 smart
dont spray it into the filter area. do the following.
*be sure to clear codes that are stored
remove old air filter
clean area and intake box with wet rag then dry
install in new air filter
buy CRC Mass Air Filter Sensor Cleaner
loosen the MAF portion of the intake by loosening the screw holding the clamp
spray 15x on one side of the MAF
spray 15x on the other side of the MAF
be sure to hit the two wires that are visible in that area
use compressed air to dry the MAF
reinstall MAF portion of intake
put back intake box
start her up
*be sure to clear codes that are stored
remove old air filter
clean area and intake box with wet rag then dry
install in new air filter
buy CRC Mass Air Filter Sensor Cleaner
loosen the MAF portion of the intake by loosening the screw holding the clamp
spray 15x on one side of the MAF
spray 15x on the other side of the MAF
be sure to hit the two wires that are visible in that area
use compressed air to dry the MAF
reinstall MAF portion of intake
put back intake box
start her up
thanks !
Carlos
Saprissa@aol.com
Trending Topics
Senior Member
Joined: Mar 2008
Posts: 289
Likes: 0
From: Queens, NYC
02 330i & 99 ML430
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Super Member
Joined: Apr 2003
Posts: 690
Likes: 33
From: Bay area - California
2000 ML320 2006 SLK 350
Changed the MAF insert this weekend....and...
Some erratic shifting in the first 50 miles of driving, especially noticable, when starting from a complete stop on red lights...tranny shifting quite jerky...also mileage continued to drop down in that period all the way to 15.5 mpg city.
After that, erratic shifting is gone....and trip computer recorded mileage 22 mpg highway after the first 100 of driving on freeway, same as it was before with the old MAF & no CEL after climbing up to 8000 feet altitude, as it used to happen with the old MAF.
I think, the MAF replacement project is a success...
After that, erratic shifting is gone....and trip computer recorded mileage 22 mpg highway after the first 100 of driving on freeway, same as it was before with the old MAF & no CEL after climbing up to 8000 feet altitude, as it used to happen with the old MAF.
I think, the MAF replacement project is a success...
Will let you know, if there is any dramatic change in preformance...
I have been monitoring the mileage through my trip computer...and its about right for my 320....21 mpg on freeway, 18 in city...the torque & power hasn't felt much different from when it was new either.
I do however understand that a failing MAF will throw the ECU off in determining the correct fuel-air ratio...thereby directly impacting efficiency, power, torque and a lot more...
Early wear of the oxygen sensors, catalytic converters, spark plugs etc. A faulty MAF can indeed cause a lot of ill effects...
I have used my judgement & experience gained through changing other parts of the fuel burning system (spark plugs, cats & MAF cleanups) to determine, when was the right time to say goodbye to the MAF and replace it for good.
I have been monitoring the mileage through my trip computer...and its about right for my 320....21 mpg on freeway, 18 in city...the torque & power hasn't felt much different from when it was new either.
I do however understand that a failing MAF will throw the ECU off in determining the correct fuel-air ratio...thereby directly impacting efficiency, power, torque and a lot more...
Early wear of the oxygen sensors, catalytic converters, spark plugs etc. A faulty MAF can indeed cause a lot of ill effects...
I have used my judgement & experience gained through changing other parts of the fuel burning system (spark plugs, cats & MAF cleanups) to determine, when was the right time to say goodbye to the MAF and replace it for good.
