CEL!!
Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
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From: Mississippi
2004 SL55
CEL!!
I was driving to work this morning and noticed my car begin to idle rough at the stop light. I proceed to ease into the throttle when the light turns green and about 2 miles down the road the CEL starts blinking, turns solid for a few minutes, and begins to blink again. I take the car to my mechanic to pull the codes and it turns out there are 12 codes! Cylinders 1,3, and 4 misfire, general cylinder misfire, multiple cylinder misfire, etc.
Any clue what this might be? Vacuum leak maybe? The car has 81k miles, so I went ahead and ordered new plugs. Any help would be great.
Any clue what this might be? Vacuum leak maybe? The car has 81k miles, so I went ahead and ordered new plugs. Any help would be great.
Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
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From: Mississippi
2004 SL55
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From: Salt Lake City (but not Morm)
2003 E55 & 2014 GL550
True! Cant hurt with 80k.
Quick question. Did you wash the car or drive in rain before this happened. When I wash my car, it goes haywire now. Some wires or sensors are unhappy and it throws similiar codes. Not sure what is causing it but I have learned to live with shutting the car off when I wash it in touchless wash.
Clear the codes and see if they come back. Of COURSE check those plugs when you pull them and see how they look. Should be fine though. We have lots of stories of pistons going....never 3 in row.
Quick question. Did you wash the car or drive in rain before this happened. When I wash my car, it goes haywire now. Some wires or sensors are unhappy and it throws similiar codes. Not sure what is causing it but I have learned to live with shutting the car off when I wash it in touchless wash.
Clear the codes and see if they come back. Of COURSE check those plugs when you pull them and see how they look. Should be fine though. We have lots of stories of pistons going....never 3 in row.
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Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
Likes: 0
From: Mississippi
2004 SL55
True! Cant hurt with 80k.
Quick question. Did you wash the car or drive in rain before this happened. When I wash my car, it goes haywire now. Some wires or sensors are unhappy and it throws similiar codes. Not sure what is causing it but I have learned to live with shutting the car off when I wash it in touchless wash.
Clear the codes and see if they come back. Of COURSE check those plugs when you pull them and see how they look. Should be fine though. We have lots of stories of pistons going....never 3 in row.
Quick question. Did you wash the car or drive in rain before this happened. When I wash my car, it goes haywire now. Some wires or sensors are unhappy and it throws similiar codes. Not sure what is causing it but I have learned to live with shutting the car off when I wash it in touchless wash.
Clear the codes and see if they come back. Of COURSE check those plugs when you pull them and see how they look. Should be fine though. We have lots of stories of pistons going....never 3 in row.
With my luck I'll be the first person to lose 3 pistons at once!
Thanks guys!
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Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
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From: Mississippi
2004 SL55
My mechanic replaced the plugs and cleared the codes. The CEL is still on, w/ the same codes being pulled (misfire in 1,3, & 4, multiple cylinder misfires, etc.). He said that the plugs on the passenger cylinder bank were darker than the plugs on the driver cylinder bank. I just had long-tubes installed and had EC shelf tune the car remotely. Do you think those cylinders are running too rich and it could be fixed by having Jerry lean out the tune?
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From: London, UK
No longer stock '06 E55, A3 3.2 Quattro, GLE 400d, R107 280SL, Golf Polo
Those codes also occur with my water meth kit occasionally - although doubt its related to yours.... but just putting it out there in case it helps.
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From: Houston
2003 W211 E55, 2003 W220 S600
seems like an electrical issue.
hopefully you didnot injest water while driving in the rain, i know it is hight unlikely. do a compression test.
hopefully you didnot injest water while driving in the rain, i know it is hight unlikely. do a compression test.
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From: Treasure Island, FL
GLE 63S
So did this happen right after the tune and LT's were installed. How many miles did you drive after the work was done? When doing my valve cover gaskets and replacing the fuel rail I bumped the small tube under the TB that goes into the blower. This casued similar issues to what you are experiencing. I called Shardul and he said check the small tube under the TB and make sure it's inserted into the blower housing. And what do u know issues gone.
Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
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From: Mississippi
2004 SL55
So did this happen right after the tune and LT's were installed. How many miles did you drive after the work was done? When doing my valve cover gaskets and replacing the fuel rail I bumped the small tube under the TB that goes into the blower. This casued similar issues to what you are experiencing. I called Shardul and he said check the small tube under the TB and make sure it's inserted into the blower housing. And what do u know issues gone.
Thread Starter
Super Member
Joined: Feb 2010
Posts: 554
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From: Mississippi
2004 SL55
Apparently this will cause a misfire CEL (obvious sarcasm)...Mechanic's write-up:
Checked for fault codes. Found misfire codes for all cylinders. Checked actual misfire values while running. All cylinders intermittently misfire. Tested coils and spark plugs. Checked condition of spark plugs. Coils, wires, and spark plugs ok. Spark plugs indicate an extremely rich mixture. Check O2 sensors. O2 sensors before the catalyst (front) malfunctioning. O2 sensors were noted to be installed backwards. Front O2 sensor installed in rear, rear installed in front. Wiring was cut and extended by exhaust installer. Connector ends installed on wrong sensor. Rewired connectors and installed sensors correctly. Pins #1 and #2 switched / crossed on front sensor. Swapped wire #1 and #2. Cleared codes and test drove. Vehicle idles and runs normally now. No misfires detected.
Checked for fault codes. Found misfire codes for all cylinders. Checked actual misfire values while running. All cylinders intermittently misfire. Tested coils and spark plugs. Checked condition of spark plugs. Coils, wires, and spark plugs ok. Spark plugs indicate an extremely rich mixture. Check O2 sensors. O2 sensors before the catalyst (front) malfunctioning. O2 sensors were noted to be installed backwards. Front O2 sensor installed in rear, rear installed in front. Wiring was cut and extended by exhaust installer. Connector ends installed on wrong sensor. Rewired connectors and installed sensors correctly. Pins #1 and #2 switched / crossed on front sensor. Swapped wire #1 and #2. Cleared codes and test drove. Vehicle idles and runs normally now. No misfires detected.
Last edited by rlh23; Aug 3, 2011 at 11:05 AM.
