Hi everyone, I am new to these forums, thanks for reading. I just had my check engine lamp light up in my 1998 ML 320. There doesn't seem to be anything wrong with my truck. What are the possible codes that it could be, what could set off the check engine light? Any help would be appreciated!
Thanks.

You have to pull codes to get the scoop on what is setting it off...failure of one or more emission control components will set this off...

...that said, other than the obvious issue of a gas cap that isn't secured properly, the only "guess" diagnosis would be either an oxygen sensor or the MAS or mass air sensor. My money is on the MAS failure. Part goes for over $600 I believe.

Again, the codes will tell you what emission component is causing the problem.

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Powder,

I had the same experience with my '98 about a year-and-a-half ago. It was the Mass Airflow Sensor, which cost $357 for the part and $135 for labor to replace. The good news is that the problem has not recurred since.

MAF can be obtained from many discount parts sources for about $200.

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)

Do not buy one on ebay....this is one of many parts than can look brand new but be DOA. Lots of complaints. Go to Autozone and have them read the fault codes and reset the CEL (free). They will probably tell you O2 sensors but don't be too quick to buy FOUR.

I paid $240 on-line for my MAF for an ML430. This is at MOST a 5 minute job to replace and you only need a screwdriver. It will take you longer to clean up than it will to install the part.

I believe my fault codes were P0173 and P0170. Get new MAF, install it, have autozone reset the CEL and the engine computer will take it from there.

I did my repair 12 months/14,000 miles ago....no problems with CEL since then.

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Jim

Thank you very much, I will get the codes checked out this week-end!

Just had the same thing happen to our '99 yesterday while at the autocross (I was running my MX5 not the ML.. hahah er.. anyway.) I'm going to go and get the codes read today if I can. Thanks for the info post. Once I get the codes I take it there is a link somewhere that I can decode them.

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My EGR tube was plugged solid. the light was on and it started to idle rough.
took it off and cleaned it- that was 20,000 miles ago.
smooth sailing.

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles

OK, so we are in one of the counties of WA that got the bad Conoco/Philips gas and we buy it at Safeway (which resells thier gas). S Conoco/Philips said that we should take the car to the dealer (60 miles away) and they will flush the fuel system on Conoco's dime. What is really odd is that the wife says that the light has stopped coming on now that the current tank of fuel is nearly gone.

Odd.. very odd..

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The only thing in my life consistant IS inconsistancy,
(Todays electronics and a wife and 2 daughters)

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles