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Discussion Starter · #1 · (Edited)
Hi needing a little guidance....
Recently I’ve been experiencing really light kick back whenever I’d come to a stop. Started slow, wouldn’t happen all the time but I did notice. Last week it was every time and by Thursday evening my engine light was flashing, engine was full on shaking and trying hard not to cut off. My husband has a reader and scan tool, he’s changed the spark plugs (Found significant amounts of oil in wells from previous oil change) and ignition coils. The car is no longer struggling to keep running but still misfiring when idle. Please help!

UPDATE
Engine light went off, misfiring stopped. My husband drove her for two whole days, filled tank for me! Day three (today) I drive in the morning, the misfiring starts again 🙄 by the afternoon the misfiring is consistent and I start smelling fuel. Only heavily misfires at low speeds and idle, by the time I returned home my gas light was on! Which never happens! My model is also the flex fuel so I do use E85
Codes: P0300, P0301, P0303, P0304
 

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any fuel related codes?
any issues when filling up at gas pump?
 

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Hi needing a little guidance....
Recently I’ve been experiencing really light kick back whenever I’d come to a stop. Started slow, wouldn’t happen all the time but I did notice. Last week it was every time and by Thursday evening my engine light was flashing, engine was full on shaking and trying hard not to cut off. My husband has a reader and scan tool, he’s changed the spark plugs (Found significant amounts of oil in wells from previous oil change) and ignition coils. The car is no longer struggling to keep running but still misfiring when idle. Please help!
Not sure where you got the plugs, but the CLA requires original mercedes plugs , branded oem will not do. The specific grooving on the plugs ensure proper alignment of the tip. You will cause misfiring if improper installation of non-factory plugs are used. Speaking from experience.
 
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Not sure where you got the plugs, but the CLA requires original mercedes plugs , branded oem will not do. The specific grooving on the plugs ensure proper alignment of the tip. You will cause misfiring if improper installation of non-factory plugs are used. Speaking from experience.
i will tag the ground strap position when the oem plugs come out ... which should be the same when the new plugs go in
else those new plugs get replaced
though i have not had any luck tracking down the angular position tolerance, very irritating
 

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Discussion Starter · #6 ·
Hi needing a little guidance....
Recently I’ve been experiencing really light kick back whenever I’d come to a stop. Started slow, wouldn’t happen all the time but I did notice. Last week it was every time and by Thursday evening my engine light was flashing, engine was full on shaking and trying hard not to cut off. My husband has a reader and scan tool, he’s changed the spark plugs (Found significant amounts of oil in wells from previous oil change) and ignition coils. The car is no longer struggling to keep running but still misfiring when idle. Please help!

UPDATE
Engine light went off, misfiring stopped. My husband drove her for two whole days, filled tank for me! Day three (today) I drive in the morning, the misfiring starts again 🙄 by the afternoon the misfiring is consistent and I start smelling fuel. Only heavily misfires at low speeds and idle, by the time I returned home my gas light was on! Which never happens! My model is also the flex fuel so I do use E85
Codes: P0300, P0301, P0303, P0304
 

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UPDATE
.....My model is also the flex fuel so I do use E85....
Welcome to the CLA Forum FlvyFRee :)
What city are you near?
Which year and model CLA do you have?
 

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a) "Significant oil in wells...from oil change" may point to improper maintenance in the past.
b) Suggest you track down the source fuel smell immediately.
c) The misfire codes might be related to the plugs...also suggest a trip to the dealer might be in order to help with these issues, for your safety.
 

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Were original Mercedes spark plugs used? As per my recent post here , I indicated that this particular turbo engine requires Mercedes spec'd plugs, not the oem plugs you would buy from the regular car parts srore, even though the NGK catalogue will say that it fits the mercedes CLA.
Like I said, from my experience with plug change, when I used non-mercedes factory plugs, and just bought NGK oem plugs , gasoline smell could be detected and the car was idling rough, gas mileage was poor.
The price of the mercedes plugs is not that much more than the plugs you pay for a oem plug at the general parts store.
 
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Hi needing a little guidance....
Key "SPARK PLUG - GROUND ELECTRODE ORIENTATION" in the search field above and find the new topic started today by @jmc which shows the photo using the OEM tip orientation compared with another brand.
 
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