2010 GLK Misfire/Shaking
 

2010 GLK with 99,000 kilometres...
Misfiring and shaking badly..
Non-MB code reader spit out:

Intermittent misfire in 1,2,3 cylinders

Bank 1 system too lean

Post catalyst fuel trim system too lean

P0301, P0302, P0303

Anybody have any experience with these diagnostics?

Recommended service was clean mass/airflow

Did that with carb spray, cleared codes..worked for couple hours, engine light is flashing again

any suggestions appreciated

Try cleaning it again - it may need replacing.

Extended roadside towed it today...Dealer thinks it needs spark plugs replaced..Apparently quite common for glk.
320$ for the 12 plugs/labour...Also B service if 450$ here in New Brunswick Canada

quite common? :O I'll have to keep an eye out. So far I've been lucky with 110k km on mine. You think the massive snow/cold you got out there in NB this season could have exacerbated it?

Couldn't say for sure, although it was -30 Celsius (wind chill) or colder for over 70 days....

What gas are you using and did you buy some at a different station recently?

No, same station, same fuel...I was suspicious of that myself!!

Dealer is replacing 6 plugs and an O2 sensor...
As well as both front struts and a 4 wheel alignment

Struts and O2 are covered by extended warranty, plugs and wheel alignment aren't....
168.99$ for alignment...lol

yep, sounds like your in need of some new spark plugs...i had mine changed at the 58,000 mile mark.