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Ask Lou P. master tech Your Own Question
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 3740
Experience:  15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
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Rob ***** *****: 1999 MB C230 Kompressor, runs fine until I

Customer Question

Rob ***** *****: 1999 MB C230 Kompressor, runs fine until I press accelerator to pass, then one cylinder drops out and I run on 3. Restart the car and it runs fine again. The error code says #3 is misfiring. I replaced, the spark plug, coil pack, fuel injector and mass flow one at a time and restarted. Each time I get #3 cylinder not firing. What's the next step in troubleshooting?
JA: Thanks. Can you give me any more details about your issue?
Customer: I've read other questions on this site and they all seem to lead to the coil pack. I replaced it and still have same problem.
JA: OK got it. Last thing — Mercedes Mechanics generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 10 months ago.
Category: Mercedes
Expert:  Lou P. master tech replied 10 months ago.

Hello. So are you actually erasing the code and it keep coming back ? Do you feel the engine misfiring ?

Customer: replied 10 months ago.
I clear the code each time I make change. Everything runs fine until I press to accelerate up a hill or to pass. Every time the code says cylinder 3 misfire P0303.
Expert:  Lou P. master tech replied 10 months ago.

OK, so if you replaced all those parts, that means that it will be mechanical, so you would have to check compression and do a leak down test , its possible you have a valve issue, or carbon issue.