2018 GLC43 throwing code P0430
Thread Starter
Newbie
Joined: Feb 2021
Posts: 6
Likes: 1
2018 GLC 43 AMG
2018 GLC43 throwing code P0430
Hi all,
the other night I was driving back on a ~75 miles trip in my 2018 GLC43 AMG— ambient tempts hovered around -25* F….
Everything worked perfectly until the exit ramp within a mile of my home when the engine began missing on acceleration and idle, and could barely idle.
Check engine light began blinking and then became perminately illuminated.
Limped the last mile home and barley made it up the drive and parked it in the heated garage.
Opened hood after smelling burning smell to a glowing red hot precat/cat off of left side
manifold.
The morning morning after, everything is absolutely perfect with no CEL. My wife drove the car for a short while only for the CEL to pop back on.
Initially I thought maybe frozen MAF or inability to calculate air/fuel ratio due to air density-
scanned it and got code P0430 cat system efficiency below threshold bank 2 (left side)
I’m confused as I had no misfire codes.
has anyone dealt with a clogged cat on an M276?
i appreciate any insight.
Thank you!
the other night I was driving back on a ~75 miles trip in my 2018 GLC43 AMG— ambient tempts hovered around -25* F….
Everything worked perfectly until the exit ramp within a mile of my home when the engine began missing on acceleration and idle, and could barely idle.
Check engine light began blinking and then became perminately illuminated.
Limped the last mile home and barley made it up the drive and parked it in the heated garage.
Opened hood after smelling burning smell to a glowing red hot precat/cat off of left side
manifold.
The morning morning after, everything is absolutely perfect with no CEL. My wife drove the car for a short while only for the CEL to pop back on.
Initially I thought maybe frozen MAF or inability to calculate air/fuel ratio due to air density-
scanned it and got code P0430 cat system efficiency below threshold bank 2 (left side)
I’m confused as I had no misfire codes.
has anyone dealt with a clogged cat on an M276?
i appreciate any insight.
Thank you!
Thread Starter
Newbie
Joined: Feb 2021
Posts: 6
Likes: 1
2018 GLC 43 AMG
Unfortunatley I'm at 53k...3k out of warranty,
More unfotunately, I'm about 183 miles from the nearest MB dealer.. the cat/downpipe overheats and car begins stumbling within 75 miles as I've found.
The car right now is at an independent 'european car' shop
I have a theory-- Plugs have not been changed and its at 53k... maybe a subltle missfire due to fouled plugs led to fuel burning in cat, overheating and melting metals...
Fix will likely be plug replacement and new downpipe/cat. -- hopefully we'll see if my theory holds any water
More unfotunately, I'm about 183 miles from the nearest MB dealer.. the cat/downpipe overheats and car begins stumbling within 75 miles as I've found.
The car right now is at an independent 'european car' shop
I have a theory-- Plugs have not been changed and its at 53k... maybe a subltle missfire due to fouled plugs led to fuel burning in cat, overheating and melting metals...
Fix will likely be plug replacement and new downpipe/cat. -- hopefully we'll see if my theory holds any water
Member
Joined: Oct 2013
Posts: 91
Likes: 23
From: Tucson, AZ
2021 GLC43; 2014 CLS 550/C218; 2012 E350/C207
Sorry to hear you missed the warranty, keep us informed, would like to hear the outcome, maybe somebody else can provide worthwhile advice. 50K on the plugs should not be real bad? Good luck!
Junior Member
Joined: Jul 2021
Posts: 53
Likes: 8
AMG GLC 43
I had a similar situation at 51k with my 2013 Audi S4 where my water pump blew... known problem with that gen. I talked to dealer, they took off about 30% of the cost for replacement and then I said "heck, what do i have to lose?" so I called Audi corporate who gave me another $500 cash gift card since they couldn't pay directly for the repair. Cost came down to like 200 bucks from 1400 or so. Worth a shot!
