i experienced random misfire. car was running rough as heck.
changed spark plugs, then changed the coils left and right, new fuel filter, then new MAF.

What happens is: i start the car, it runs great like a cl600 should. then after a while(1 min), the car starts to putter. i know the car is gettin air. Ignition is there. now i would think it could only be a fuel pump. right? Does a 2001 cl600 have a Fuel pressure regulator?

also before i got a 0410 and p0300. could it be a egr valve problem?

what do you think?

thank you.

 

have the same prob have changed many things that the main dealer has told me to o2sensors x8 ,coil packs ,injector seals ,think i have pin pointed the prob underneath the throttle actuator there is a small one way valve (secondry air valve )have it on order will let u no

 

P0300 is a multi cylinder misfire.
First thing to check would be the CPS crankshaft position sensor (at about $50).
Second thing would be the throttle position sensor ( valve body) (at about $1,400)
I don't have big 8 cyl. as you guys, but all the Mercedes engine firing controls are same.
Engine surges and/or runs irregularly at iddle speed (occasionally), throttle valve actuator is noisy: damage code 14 031 73 Replace throttle valve actuator.
Usually no DTC is stored. In some cases DTC P0300-P0308 may be stored (A-misfire)

P0410 is the secondary air injection pump.
Try to turn it by hand if it is functional mechanically. It should be runing on cold start.
Check the fuse for it if it's not blown.
It could be also bad oxygen O2 sensor.

 

thanks for the reply
but wouldnt the cps show on a dtc test??????
car drives good some days others really bad still waiting on air valve

 

I have the same problem with my '01 cl600. Runs great then at idle randomly misfires and when I turn it off and on again it goes back to great... had the O2 sensors and air mass meter done but only made it worse! Agree with the earlier post fuel supply/pressure makes sense. Has anyone had any success at fixing it yet? Thx