P0306 and P0173 :(
Thread Starter
Newbie
Joined: Nov 2007
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C320
P0306 and P0173 :(
Hi all,
My car is throwing:
P0306 (Cylinder 6 Misfire Detected)
and
P0173 (Fuel Trim Malfunction (Bank 2)
the car shakes real bad when I try to start it and one time, some black smoke came out of the tailpipes. Its hard to get it started as well.
If any of you know of a remedy to this, please let me know..
thanks in advance.
My car is throwing:
P0306 (Cylinder 6 Misfire Detected)
and
P0173 (Fuel Trim Malfunction (Bank 2)
the car shakes real bad when I try to start it and one time, some black smoke came out of the tailpipes. Its hard to get it started as well.
If any of you know of a remedy to this, please let me know..
thanks in advance.
Super Moderator
Joined: Mar 2007
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From: VA
THE C350
i don't know much about this problem but the people that do always ask for mileage and if spark plugs and wires have been replaced. another thing they always seem to recommend when having misfires is to mark the coil pack on cylinder 6 and move it to another one to see if the problem moves. if it does you found at least part of your problem.
MBworld Guru
Joined: Apr 2002
Posts: 22,058
Likes: 18
From: Diamond Bar, CA
W206 PHEV AMG
#6 misfire and bank 2 fuel trim error...
fuel trim code could be clogged injectors, but black smoke = too much fuel. fuel trim code might be due to the computer unable to tell #6 injector to shut down for some reason. usually if the cylinder is misfiring the computer would tell that cylinder to turn the injector off after few seconds to prevent flooding the cylinder.
bank 1 = 1, 2, 3 cylinder (fuel door side)
bank 2 = 4, 5, 6 cylinder (no fuel door side/driver side for left hand drive)
if you want you can start by swap coil pack with another cylinder. check your wires for resistance and check the plugs. if those check out okay start looking into your valve springs and rocker arms. The cam on the regular M112 is one piece, so no worry about that.
fuel trim code could be clogged injectors, but black smoke = too much fuel. fuel trim code might be due to the computer unable to tell #6 injector to shut down for some reason. usually if the cylinder is misfiring the computer would tell that cylinder to turn the injector off after few seconds to prevent flooding the cylinder.
bank 1 = 1, 2, 3 cylinder (fuel door side)
bank 2 = 4, 5, 6 cylinder (no fuel door side/driver side for left hand drive)
if you want you can start by swap coil pack with another cylinder. check your wires for resistance and check the plugs. if those check out okay start looking into your valve springs and rocker arms. The cam on the regular M112 is one piece, so no worry about that.
Last edited by FrankW; Oct 2, 2009 at 06:48 AM.
Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
As our learned friends have commented. Check coilpacks, wires, plugs on number 6.
Clean & check MAF - try unplugging & running on a default map.
You might have a faulty upstream O2 sensor on bank 2 or clogged injector as Frank says - dose with Techron.
Outside chance of a faulty CPS.
Clean & check MAF - try unplugging & running on a default map.
You might have a faulty upstream O2 sensor on bank 2 or clogged injector as Frank says - dose with Techron.
Outside chance of a faulty CPS.
Super Moderator
Joined: Jun 2008
Posts: 19,942
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Check pressure on the fuel rail - approx 50 PSI - If you had more cylinders misfiring I would suspect fuel pump or fuel filter but you might have one injector right on the edge that is not happy with supply pressure. Black smoke denotes too much fuel - however - not too little. Your fuel pressure regulator is in the filter.
Edit - deposits in injectors can cause them to dribble & not shut off correctly.
Another issue that frequently causes black smoke & overfueling on these cars is the temperature sender unit. When it fails the car's management system thinks the engine is cold and richens the mixture causing black smoke & awful running.
Good luck!
Edit - deposits in injectors can cause them to dribble & not shut off correctly.
Another issue that frequently causes black smoke & overfueling on these cars is the temperature sender unit. When it fails the car's management system thinks the engine is cold and richens the mixture causing black smoke & awful running.
Good luck!
Last edited by Glyn M Ruck; Oct 2, 2009 at 07:01 AM.
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MBworld Guru
Joined: Apr 2002
Posts: 22,058
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From: Diamond Bar, CA
W206 PHEV AMG
As our learned friends have commented. Check coilpacks, wires, plugs on number 6.
Clean & check MAF - try unplugging & running on a default map.
You might have a faulty upstream O2 sensor on bank 2 or clogged injector as Frank says - dose with Techron.
Outside chance of a faulty CPS.
Clean & check MAF - try unplugging & running on a default map.
You might have a faulty upstream O2 sensor on bank 2 or clogged injector as Frank says - dose with Techron.
Outside chance of a faulty CPS.
I was thinking it could be clogged injectors, but then he also said sometimes it would have black smoke which caused me to edited my post thinking it could be ecu fart not shutting down the injector which excess fuel caused black smoke. therefore I don't know what's the possibility of clogged injectors.
meh...I would just check everything now...LOL
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Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Sorry for the messy reply - my DSL line keeps dropping out today - many edits & mess ups my side - not the way to help a member - LOL
Last edited by Glyn M Ruck; Oct 2, 2009 at 07:05 AM.
MBworld Guru
Joined: Apr 2002
Posts: 22,058
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From: Diamond Bar, CA
W206 PHEV AMG
that probably explained why it's misfiring and still flooding.
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C320
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From: Houston, TX
2019 E450 Sedan 4Matic
I recently had this problem, except I had 3 cylinder misfires and P0173 with shaking to eventual stall while I was on the road. I would clean MAF with spray, replace fuel filter if you haven't done recently. My CEL went away but I don't know if the problem was fixed for sure or not.
