P0172 & P0175 Too Rich after spark plug change
10-12-2018, 07:35 PM
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2010 E550 Sedan
P0172 & P0175 Too Rich after spark plug change
New to the forum, new MB owner. 2010 E550 Sedan, 66k miles. Changed the plugs, car drove fine for ~30 miles. Next day, starts to idle rough and check engine light comes on. I removed and reinstalled all plug wires to ensure they were seated properly. I have read the available information which can point you in a lot of directions. Running reach after changing the plugs seems to me that something is not firing correctly thus running rich. Anyone else run into this before. Any help greatly appreciated.
10-12-2018, 09:18 PM
#2
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What plugs did you install?
Its sometimes related to mass airflow sensor not reading correctly. In this case are you sure that nothing was unplugged other than coil packs and that the air cleaner housing was securely attached? On my e350 the housing has a clip at the back to ensure that it fits snugly onto the MAF. Not sure on 550 but I'm betting it also has to fit well. Housing has a rubber collar for a complete seal to MAF.
Its sometimes related to mass airflow sensor not reading correctly. In this case are you sure that nothing was unplugged other than coil packs and that the air cleaner housing was securely attached? On my e350 the housing has a clip at the back to ensure that it fits snugly onto the MAF. Not sure on 550 but I'm betting it also has to fit well. Housing has a rubber collar for a complete seal to MAF.
Last edited by Mud; 10-13-2018 at 12:42 PM.
10-13-2018, 01:43 PM
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2010 E550 Sedan
What plugs did you install?
Its sometimes related to mass airflow sensor not reading correctly. In this case are you sure that nothing was unplugged other than coil packs and that the air cleaner housing was securely attached? On my e350 the housing has a clip at the back to ensure that it fits snugly onto the MAF. Not sure on 550 but I'm betting it also has to fit well. Housing has a rubber collar for a complete seal to MAF.
Its sometimes related to mass airflow sensor not reading correctly. In this case are you sure that nothing was unplugged other than coil packs and that the air cleaner housing was securely attached? On my e350 the housing has a clip at the back to ensure that it fits snugly onto the MAF. Not sure on 550 but I'm betting it also has to fit well. Housing has a rubber collar for a complete seal to MAF.
