Weird misfire and intake codes
Thread Starter
Junior Member
Joined: Mar 2018
Posts: 21
Likes: 0
2008 Mercedes c300
Weird misfire and intake codes
Hi guys. My car drives pretty fine while cold. As soon as it gets warm (over 80) and I come to the stop light and stay there for like 20-30 seconds, ECU light starts flashing and maybe about 3-4 seconds after that, my car starts shaking pretty bad. Then it doesn't stop shaking on stops until it cools down (or until ECU resets I guess). It seems like it has good power even when this starts happening. When I take off the car drives fine. I scanned it and codes were Misfire on cylinder 2, misfire on cylinder 6, then P2015 "Intake Manifold Runner Sensor Switch Circuit Range / Performance B1", and P0420 "Catalyst System Efficiency Below Threshold Bank 1". I also replaced the fuel injector, plug and coil on cylinder 2, that didn't fix it.
Super Member
Joined: Jun 2017
Posts: 608
Likes: 107
From: Western NC
2009 MB C300 Sport 4matic
Good possibility the plastic flap valve actuator arm broke..located on intake runner,IM..fairly common on these c300/350's with higher mileage. Do a Search and you'll read all about it.
Thread Starter
Junior Member
Joined: Mar 2018
Posts: 21
Likes: 0
2008 Mercedes c300
Did reasearch already and figured out I simply forgot to plug in connector at the back of the engine. Now back to misfire on cylinder 2 only. Can slightly lower compression on that cylinder make it miss? and why does the car run pretty good until I come to red light and have it stopped in D. Then ECU light starts flashing and car starts shaking crazy. Does ECU shut down whole cylinder after it realizes its missing in low rpms (500, if above 600 ecu light will never come on and car will drive fine)...
Super Member
Joined: Mar 2012
Posts: 535
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From: Franklin, MA
2006 CLK 350/. 2009 CLK 350/2005 Both White
Last edited by karayjay; Aug 9, 2019 at 11:16 AM.
Super Member
Joined: Mar 2012
Posts: 535
Likes: 13
From: Franklin, MA
2006 CLK 350/. 2009 CLK 350/2005 Both White
On a side not since I saw the post from antesusic21 I do get another code with my misfire code it a low coolant temp error P0128 low coolant temp even after it is wormed up? and the other is the misfire P0301 cly 1 misfire
