CEL on 1999 ML430 with 115,000 miles turned on with P0130 (before cat O2 sensor, bank 1) and also showing P0301, P0304, P0303 and P0300 codes.

CEL reset 30 miles ago and has not yet turned on again. Vehicle is starting and running smoothly, no stumbling or hesitation and no unusual smoke out the tailpipe. Fuel economy (well not really economy) is normal. MAF was replaced 50,000 miles ago and plugs (Bosch Platinum +2) at 100,000 miles. Burning 93 octane fuel.

Anyone suspect this is a problem with something other than an O2 sensor that is failing?

Thanks.

__________________
Jim

Jim,
That is somewhat common, has your ML had the catalyst recalls done?
Most likely a plugged exhaust on that side (right).

__________________
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Unfortunately, my 1999 ML430 is supposedly not covered by the recall. My model and VIN are in the right "range" but VMI indicates my VIN is not included in the recall. I am really frustrated by this because I have a cracked cat on the drivers side. I've just taken pictures of it and the crack is IDENTICAL to the one shown in Fig 3 of the Procedure documents for the SC-200560014.

The dealer first said they could find no problems. Another trip to the dealer convinced them there is a leak at the driver's side cat but they said I'm not included in the recall. Couldn't even buy a new assembly. They claim they have another customer backordered since December.

I plan to send Mr. Ernst Lieb (new MBUSA CEO) and Klaus Ulkmann a letter requesting a further explanation as to why my VIN, with EXACTLY the same failure as those being recalled, isn't included. Any other advise from the DOC is always useful and valuable. Thanks.

Pic of my driver's side cat is attached.

Attached Thumbnails

 

__________________
Jim

code PO300

PO303, PO304 PO302 PO301 PO305

i replaced the Mass air flow sensor today. Wasted $100.

Went to autozone and the salesman said based on my multi cyl mis fires..he thought spark plugs or wires. Too hard for me to comprehend that in 20,000 miles my 12 new Bosch platinum 2 plugs all failed. And Mercedes over engineered wires ? 2 per cyl.

I accelerate really slow to keep it going. any extra gas and it mis-fires.
at stop lights when it idles rough i will restart and it idles smooth.
Go Figure. I am all ears. I just hate replacing new plugs with newer plugs. I now have a spare MAS.

__________________
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

Steve: Sorry to hear about your problems. Here's an update to my original post when I pulled those codes.

Now have 118,000+ miles and the CEL has not returned. I didn't do anything else but reset CEL and re-fueled. Suspected plug wires but still using original ones and have not yet checked resistances yet.

Also decided to fight MB later on the cat recall. Found a shop who welded the cat seam for $50. Fortunately, the crack was completely visible and had not traveled to the "non-visible" side (somehow, using the word invisible side didn't sound right). The indy shop manager said clearly looked like poor workmanship or machine improperly set.

Good luck.

__________________
Jim

thanks for the reply. my cat is covered by a recall.
but none are in stock in Western Michigan.

Please let us know when you cure your ML.

here is the link to the free cat list.

http://www.epa.gov/oms/cert/recall/420b06001.pdf page 9 is the ML's.

MISFIRED UPDATE. Replaced MAS, 2 bottles of dry gas, unplugged battery for a night. it was running better..then today..20F here..it lugged.. -- misfired -- lost power -- wouldnt accelerate as I pulled into a 4 lane. I had to move to the center lane to get out of the way. I restarted it then it was okay. Stinking computers. I think its some stinking 25 cent computer chip somewhere on some botherboard thats going to cost me thousands.

__________________
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

Bosch Platium Spark Plugs From Autozone Are Plain Junk If They Have The 2 Black Rings On The Top Of Them. Only The Platium From Mb With The Blue Rings Will Work In These Cars. I Have Fixed Many Cars By Throwing Away The Autozone Bosch Platium. The Plain Bosch Super Plugs Work Great. Platium Is Just For Long Life. I Want My Plugs Changed After 30 K Any Way.

Cat converters are warranted for 8yr/80,000 miles.

Doesn't have to be a recall for them to be replaced, just something wrong with them.

__________________
Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles