hey guys !


Currently working on my dad's 2001 CLK 320 and because I had to change the upper control arms, I had to disconnect every connector on the passenger side (ECU, BAS System, and the K40\4 fuse box)


Ever side doing this, the car has not been the same ! Idling is rough and make the car shake, I get poor gas mileage and my acceleration from standstill is really slow. It's almost like the car is struggling to get air until in reaches 2000rpm then it gets better.


I have the following codes when I scan the car:


P0135 - O2 sensor
P0203 - Cylinder 3 Injector Circuit Malfunction
P0206 - Cylinder 6 Injector Circuit Malfunction
P0300 - Random Misfire
P0303 - Cylinder 3 misfire
P0306 - Cylinder 6 misfire
P0412 - Secondary Air injection Solenoid A - circuit malfunction


So far, I have changed the MAF and change the spark plugs (they were way over due)


I also swapped the colis and the leads and those codes appears within seconds of clearing the codes and starting the car.


Not too sure what to check anymore ! All that trouble because of upper control arms !


Thanks in advance

 

Assuming all the faults were not there before all the disconnects--have you simply cleared all the faults---run the car around-----rescan---what if any faults return??

 

There was no codes or check engine prior to me making the change.

After I changed the MAF and the spark plugs, I would reset the check engine only for the light to come back blinking couple of seconds after the start up.

Scanning the car again would give me the exact same codes.

I'm wondering if a faulty sensor that I'm not aware is the issue here

 

Could be faulty or incorrectly seated sensor. What brand MAF did you buy?

 

I bought a Bosch MAF from the Euro junk yard. It help the car but it's still misfiring.

 

You have done so many things,however for sure misfires are timming issues--plugs--wires--coils bla bla

The faulty secondary air relay fault would cause the 02 sensor--on a cold start do you hear the seconday air motor come on for say 3-5 min???

I'd put the old MAF back--you don't have any MAF faults!!


bla bla bla

 

Since I did change the places of where the coils and the wires were, I don't think they are defective.

What noise am I suppose to hear from the secondary air motor ?

Is there a relay for the air motor that I have to verify ?

 

From a cold start, lift the hood and you should hear the motor run--it's meant to heat up the cat quicker---google MB secondary air system for an understanding--the relay is by the motor.

FYI the noise you should hear is the motor running, but it isn't because the relay is faulty therefore the 02 fault.

 

had to disconnect every connector on the passenger side (ECU, BAS System, and the K40\4 fuse box). check all conections make sure the k40/4 relay is conected to the right wires and check the fuses

 

Hi,

I fixed the problem. I had pins in the ECU that were bent. Once I fixed that, the car runs better than better because of the change of spark plugs. Also changed a relay and a fuse (40A Maxi)

I still have a code for the 02 sensor (bank 2, sensor 1) So I will double check for the wiring and hopefully I won't have to change it

Thanks for the helps guys !