C43 misfire nightmare (eurocharged)
Codes: p0300-p0306 (and all in between)
When?: Only with pedal to floor/full throttle. Drives %100 fine when just cruising even for long distance.
Repairs: replaced all plugs 3 times, all coils twice, all fuel injectors, maf and cps sensor
Story:
Drove my c43 for 10-12,000 miles after buying it, drove beautiful %100 perfect. Brought it into Eurocharged to get tuned and new spark plugs and within the hour after tuning it misfired. Owner of the shop said it was normal, but it kept persisting so I brought it in, they said my brand new plugs needed cleaned?. Few weeks down the road I get all new coils, maf sensor, cps sensor, and it’s still doing it. I bring it in and they say it’s the learning computer, reset it, and it does it again after I leave shop. Brought it in yet another time for diagnostic ($180 an hour) and say I need new fuel injectors (quoted at 4k). Get them, and still is misfiring! I bring it to another ec location 5hrs away, they say the first ec shop never installed proper oem plugs or coils, so they did that ($1,100) and it misfired on my way home. I’ve had it diagnosed by Eurocharged 6+ times and I just get parts thrown at my face I’m sick of it. Help what do you guys think, Eurocharged is sending me a new check valve to try.
its mind blowing how many times Eurocharged has handed me my car back and it’s been “perfectly fine” just to misfire always almost immediately after leaving shop, I’ve begged them to do a proper diagnosis especially with how much money they’ve made me literally waste, and every time it’s the most basic repair to not fix it, I’ve spent well over 5 grand because of misdiagnosis now.
Codes: p0300-p0306 (and all in between)
When?: Only with pedal to floor/full throttle. Drives %100 fine when just cruising even for long distance.
Repairs: replaced all plugs 3 times, all coils twice, all fuel injectors, maf and cps sensor
Story:
Drove my c43 for 10-12,000 miles after buying it, drove beautiful %100 perfect. Brought it into Eurocharged to get tuned and new spark plugs and within the hour after tuning it misfired. Owner of the shop said it was normal, but it kept persisting so I brought it in, they said my brand new plugs needed cleaned?. Few weeks down the road I get all new coils, maf sensor, cps sensor, and it’s still doing it. I bring it in and they say it’s the learning computer, reset it, and it does it again after I leave shop. Brought it in yet another time for diagnostic ($180 an hour) and say I need new fuel injectors (quoted at 4k). Get them, and still is misfiring! I bring it to another ec location 5hrs away, they say the first ec shop never installed proper oem plugs or coils, so they did that ($1,100) and it misfired on my way home. I’ve had it diagnosed by Eurocharged 6+ times and I just get parts thrown at my face I’m sick of it. Help what do you guys think, Eurocharged is sending me a new check valve to try.
its mind blowing how many times Eurocharged has handed me my car back and it’s been “perfectly fine” just to misfire always almost immediately after leaving shop, I’ve begged them to do a proper diagnosis especially with how much money they’ve made me literally waste, and every time it’s the most basic repair to not fix it, I’ve spent well over 5 grand because of misdiagnosis now.
I got lucky and my first tune from EC Houston was pretty good, I did a bunch of 1/4 mile data logging and sent them back the data just to be sure everything was kosher.
They were very nice to offer me an enhanced tune (I guess because I gave them so much real world data), but the instant I loaded the second tune I had massive issues, misfires, hiccups, transmission codes.
I just flashed it back to the first tune that was pretty good, and am using a JB4 on top for additional boost on the top end.
I got lucky and my first tune from EC Houston was pretty good, I did a bunch of 1/4 mile data logging and sent them back the data just to be sure everything was kosher.
They were very nice to offer me an enhanced tune (I guess because I gave them so much real world data), but the instant I loaded the second tune I had massive issues, misfires, hiccups, transmission codes.
I just flashed it back to the first tune that was pretty good, and am using a JB4 on top for additional boost on the top end.
Last edited by Rickcross; Jun 3, 2024 at 05:39 PM.
Or you can try a quality Octane booster like VP Racing Madditive Octanium.
Especially since you are only having the problem at WOT.
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where r u located at?
Last edited by MaverickC43; Jun 3, 2024 at 11:09 PM. Reason: Forgot
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Or you can try a quality Octane booster like VP Racing Madditive Octanium.
Especially since you are only having the problem at WOT.
Is it rich? Is it lean? Is the timing too retarded or advanced?
No way to know without data logs.
Is it rich? Is it lean? Is the timing too retarded or advanced?
No way to know without data logs.
Last edited by Rickcross; Jun 5, 2024 at 11:01 AM.
Last edited by Rickcross; Jun 5, 2024 at 11:01 AM.




There is only one variable you mentioned that is causing the problem yet the tuner is having you chase your tail. You had no problems or latent pending codes, installed a tune and it all went downhill. Its a bad tune, dont mess up a bunch of other parts or spend more money or time diagnosing the obvious. No need to protect a tuner by not doing proper diagnostics first (meaning reflash to reg tune before one penny was spent).
Sure its true that thousands of these "same" tunes are on cars all across the world and the fact is, it does not work 100% for all of them the same (due to differences in temperature and humidity, and running parameters defined by region) and revisions need to be made.
This is a situation where I really advocate that people have xentry personally and dont waste thousands chasing a shops poor but very expensive diagnostic procedures. Has a TPS or gas pedal been diagnosed? Has a rich or lean condition been diagnosed per MBenztech? Are the plugs fouling if the car is not taken to the misfire range at WOT?
Good Luck
There is only one variable you mentioned that is causing the problem yet the tuner is having you chase your tail. You had no problems or latent pending codes, installed a tune and it all went downhill. Its a bad tune, dont mess up a bunch of other parts or spend more money or time diagnosing the obvious. No need to protect a tuner by not doing proper diagnostics first (meaning reflash to reg tune before one penny was spent).
Sure its true that thousands of these "same" tunes are on cars all across the world and the fact is, it does not work 100% for all of them the same (due to differences in temperature and humidity, and running parameters defined by region) and revisions need to be made.
This is a situation where I really advocate that people have xentry personally and dont waste thousands chasing a shops poor but very expensive diagnostic procedures. Has a TPS or gas pedal been diagnosed? Has a rich or lean condition been diagnosed per MBenztech? Are the plugs fouling if the car is not taken to the misfire range at WOT?
Good Luck
Last edited by Rickcross; Jun 5, 2024 at 01:02 PM.
There is only one variable you mentioned that is causing the problem yet the tuner is having you chase your tail. You had no problems or latent pending codes, installed a tune and it all went downhill. Its a bad tune, dont mess up a bunch of other parts or spend more money or time diagnosing the obvious. No need to protect a tuner by not doing proper diagnostics first (meaning reflash to reg tune before one penny was spent).
Sure its true that thousands of these "same" tunes are on cars all across the world and the fact is, it does not work 100% for all of them the same (due to differences in temperature and humidity, and running parameters defined by region) and revisions need to be made.
This is a situation where I really advocate that people have xentry personally and dont waste thousands chasing a shops poor but very expensive diagnostic procedures. Has a TPS or gas pedal been diagnosed? Has a rich or lean condition been diagnosed per MBenztech? Are the plugs fouling if the car is not taken to the misfire range at WOT?
Good Luck
Is it rich? Is it lean? Is the timing too retarded or advanced?
No way to know without data logs.
Is it rich? Is it lean? Is the timing too retarded or advanced?
No way to know without data logs.





