Help please?
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W204 C63 saloon
Help please?
Hi everyone. I’ve owned my 2012 c63 for 3 months now and have aftermarket air filters. Decat the primary and secondary cats and had a stage 2 remap. The car only made 500 bhp on the dyno and afterwards we found that the car has misfires on all cylinders. We reverted the map back to standard and the problem is exactly the same . Has any one came across this before ?
Thanks in advance Ryan
Thanks in advance Ryan
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W204 C63 saloon
Thanks for your reply. The car has just hit 54,000 miles . I returned the car to stock to see if it was misfiring and when it was we loaded the map back onto it.
I’ve just bought the spark plugs to fit and if it was a bad coil what could be the chance that all 8 would develop a misfire ?
would there be anyway to check the sensors before spending loads of money, I’ve read the 02 sensors can go back but they’ve been mapped out because of the decats I think?
thanks
I’ve just bought the spark plugs to fit and if it was a bad coil what could be the chance that all 8 would develop a misfire ?
would there be anyway to check the sensors before spending loads of money, I’ve read the 02 sensors can go back but they’ve been mapped out because of the decats I think?
thanks
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2012 c63 AMG, 2011 GLK 350, 2019 GLS 450
Get new primary o2s. There are a total of 4 the rear 2 get mapped out so as not to set check engine light when your catless. They only function as telling the ecu the cats are working or not. The primary o2 do all the work of a/f ect and will cause random multiple misfires when they are bad.
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^ i concur. faulty primary oxygen sensors will cause misfires. i also did have 1 sensor that was on its way out that would cause fuel trims to go all out of whack randomly. when it would go too far one way engine would start missing. enough of this and you'll eventually get a check engine. drove around for 2-3 months until it went kapoot and would peg rich or lean after 20 minutes or more of driving.
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intake or intake gasket leaks. then replace oxygen sensors. mixture adaptation tells it all if thats with the stock tune.
500bhp isn't "bad" dont be fooled by the 500whp header tune posts. Ask them what their ET is lol. Also not all tunes and tuners are created equal just like dynos.
500bhp isn't "bad" dont be fooled by the 500whp header tune posts. Ask them what their ET is lol. Also not all tunes and tuners are created equal just like dynos.
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intake or intake gasket leaks. then replace oxygen sensors. mixture adaptation tells it all if thats with the stock tune.
500bhp isn't "bad" dont be fooled by the 500whp header tune posts. Ask them what their ET is lol. Also not all tunes and tuners are created equal just like dynos.
500bhp isn't "bad" dont be fooled by the 500whp header tune posts. Ask them what their ET is lol. Also not all tunes and tuners are created equal just like dynos.
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W204 C63 saloon
Thanks again guys. My mapper told me that the 02 sensors have been mapped out so they do not cause a engine check light as I’m completely catless. But I am assuming that they have a function like yous say to send the correct information back to the ecu?
does it sounds like mine are going bad, as they are fine for first 10/15 mins? And would they check up any codes or just the misfire counter like the photo I posted
does it sounds like mine are going bad, as they are fine for first 10/15 mins? And would they check up any codes or just the misfire counter like the photo I posted
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This might be the reason it runs fine at first.
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also the factory computer has diagnostic functions that test the sensor by altering trims. the further off the resulting readings are the further the ECU swings trims. it does this to determine health of the sensor. at some point the trims will be so far off misfiring will begin occuring. additionally once the computer determines the sensor is faulty. it will lock the long term trims to the last value presented prior to check engine light. what that means is you can be locked super rich or super lean which can cause misfire or engine damage long term. the diagnostic function in my eyes should determine final lock between this value or with factory defined mappings based off other sensors and run values but it does not.
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W204 C63 saloon
Thanks again for the replies.
i changed all the spark plugs today (which was much easier then I thought but I don’t think it has cleared the problem , tomorrow I’m going to change oil to 5w40 as it’s 5w30 for some reason at the minute as the merc dealer said it should be 5w40)
do you guys know if it’s just the primary sensors I could be looking at or do the secondary’s also send information back to the ECU?
and is there any way to test the sensors are ok without just buying new ones? sorry for All the questions .. only had the car a few month!
i changed all the spark plugs today (which was much easier then I thought but I don’t think it has cleared the problem , tomorrow I’m going to change oil to 5w40 as it’s 5w30 for some reason at the minute as the merc dealer said it should be 5w40)
do you guys know if it’s just the primary sensors I could be looking at or do the secondary’s also send information back to the ECU?
and is there any way to test the sensors are ok without just buying new ones? sorry for All the questions .. only had the car a few month!
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secondarys are only for monitoring status of catalytic converters
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2 days in a row people have had a 30w in their engine? What’s going on, don’t people read the owners manual anymore?
How long has that been in your engine?
How long has that been in your engine?
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W204 C63 saloon
So the primary’s don’t monitor the cats at all? And the secondaries can’t cause the engine to misfire ?
and I think for since the last service what unfortunately was 6k ago . I questioned the garage I bought it from and he said it was Right and was 5w30.ive for 5w40 millers nanodrive going in . The car literally warms up in a minute ..
and I think for since the last service what unfortunately was 6k ago . I questioned the garage I bought it from and he said it was Right and was 5w30.ive for 5w40 millers nanodrive going in . The car literally warms up in a minute ..
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Correct. Primaries measure AFR before the converters to adjust fueling fuel trims. These could cause misfires if they are bad. The downstream O2 sensors are only there to make sure your converters are actually working. They are not used for fueling at all.
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So the primary’s don’t monitor the cats at all? And the secondaries can’t cause the engine to misfire ?
and I think for since the last service what unfortunately was 6k ago . I questioned the garage I bought it from and he said it was Right and was 5w30.ive for 5w40 millers nanodrive going in . The car literally warms up in a minute ..
and I think for since the last service what unfortunately was 6k ago . I questioned the garage I bought it from and he said it was Right and was 5w30.ive for 5w40 millers nanodrive going in . The car literally warms up in a minute ..
https://bevo.mercedes-benz.com/bevol..._en.html#close
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W204 C63 saloon
Thankfully the sensors don’t look to expensive.. is the only way to tell if there bad is the codes? All it has is random misfires on all cylinders and no codes.. don’t know what else it could be
and what head aches Are you talking about 😟? I’ve already bought the oil now Lol.. ran it in my big turbo cupra for years with out any problems
and what head aches Are you talking about 😟? I’ve already bought the oil now Lol.. ran it in my big turbo cupra for years with out any problems
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Thankfully the sensors don’t look to expensive.. is the only way to tell if there bad is the codes? All it has is random misfires on all cylinders and no codes.. don’t know what else it could be
and what head aches Are you talking about 😟? I’ve already bought the oil now Lol.. ran it in my big turbo cupra for years with out any problems
and what head aches Are you talking about 😟? I’ve already bought the oil now Lol.. ran it in my big turbo cupra for years with out any problems
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Seat/Leon Cupra is a Spanish version of the VW Golf GTI 1.8t from what I recall.
Last edited by hachiroku; Jun 26, 2020 at 07:16 PM.
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There was a detailed thread about it a while back. Maybe by @Vladds ?
