How to Change Spark Plugs: Mercedes C250 W204 P0303 Engine Code

Did you get the dreaded P0303 Engine Code engine fault from your OBD2 reader? P0303 Cylinder 3 misfire Detected Error is very common and often means your spark plugs need to be changed. There are other causes of P0303 cylinder 3 misfire detected errors, this how to video shows you How to Change Spark Plugs from P0303 Engine Code. While specific to changing spark plugs in a Mercedes C250 W204 model, these car repair tips apply to changing spark plugs in many other cars, as well as using OBD2 readers, and all the dos and don'ts with installing new spark plugs.
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What causes a cylinder misfire:
The car repair cylinder misfire fix requires knowing what causes a cylinder misfire. Mercedes W204 C250 cylinder misfire, like other cars, 90% of the time the problem is because your spark plugs are worn down or have carbon deposits on them, and need to be changed. Today this Mercedes C250 w204 engine's spark plugs will be changed. The W204 refers to the engine type that is common among certain model trims of Mercedes base models. So some owners have a W204 engine, and others for an E-Class Mercedes have a W212 engine.
How to change spark plugs on Mercedes C250
Keep in Mind this spark plug change is for the Mercedes W204 C250 car models, but even though your car might be different, these instructions for how to change spark plugs apply to all car engines, specifically our spark plug tips and advice on how to perform the steps properly. When your yellow check engine light turns on and you know you need that W204 spark plug change, what do you do if you don't how to change spark plugs? This video will help you on your way with your Mercedes spark plug replacement for the W204 C250. Now there is no more p0303 cylinder 3 misfire detected in your engine.

[@carbuying]

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[@danpack2518]

dont need to buy a e-8 socket, a 1/4 in socket works perfectly

[@SsgtHolland]

What a great tutorial! No fluff, but each detail demonstrated, great help!

[@VikingRasbornStrong]

Excellent clear methodical great shots. Thanks for links.

[@carbuying]

Glad it was helpful! Thanks for watching Torsten!

[@pedraw]

Cool.I wish my F 150 was so easy......you do a great job of explaining procedures.

[@carbuying]

Thanks Pedraw, glad you liked it!

[@virasinhvongkhamchanh9486]

Very nice video. Very informative clear step by step , explaining in details. Thank you, and I just subscribed. 👏👍

[@carbuying]

Welcome aboard and glad you liked the video

[@ericksanchez7751]

If you don’t have an E8 you can use a 1/4 socket. Works just fine

[@AlexHernandez-ob5cm]

Thank you u save me a lot of money

[@carbuying]

Glad t help!

[@sebastianlopeztorres1692]

Hi , excelent Video, what is the sequency of the cylinders whats is for exam ple the cylinder two ?

[@ailhamtiara]

i have 2012 C250 with code P0420 which says catalytic converter bank 1 is below threshold. Has anyone have that issue before? if so, is it confirmed bad cats or could it be the o2 sensor? Much Thanks!

[@gwcoolduude]

thanks for your help it was very informational that was cool, i did laugh when you took off the first spark plug out and all those baby flies came out that was funny !!!!!!!!!! anyway stay cool dude 🍎🍋🍏

[@branmaldo1821]

hey @carbuyingtipscom, this is probably a silly question but I am trying to DIY here and save a $500+ expense for a potential misfire issue. Bought a scanner that I am going to test out to see if I can trigger a code. If the plugs/coil do indeed need to be changed, must I disconnect the battery first before completing the work?

[@carbuying]

We did not see any reason why you would have to just connect the battery before changing those

[@slengoslengaw8510]

Need help:have p303 and p313 (misfire with active fuel reserve signal). any ideas on how to solve? Much appreciated

[@carbuying]

First of all, fill your fuel tank with premium gas, you should not be at a low fuel level anyway. If low on fuel, and the fuel pump isn’t giving enough fuel to run efficiently. Other reasons include ignition coils faulty, preventing ignition in their cylinders, Spark plugs are dirty, and or need to be changed, which the P0303 error code is telling you anyway. Possible ignition cable cracked with weak spark or no spark to its spark plug. Fuel injector is failing or clogged and might need to be cleaned. I'd start with filling tank first, then checking and changing spark plugs, see how that works, and go from there. The engine control module is internally faulty.

[@irnelhuseinovic6380]

anybody know the order of his coil packs i’m trying to figure it out but can’t seem to find it anywhere online

[@SanDiegoOfficial]

I feel like I have the same spark plug socket but it feels like it just won't go all the way down to actually grab and spin it. Did you buy an extra long one? Mine says Duralast 5/8 75-503

[@carbuying]

Try a deeper extension, and make sure your socket fits over the spark plug.

[@ifdaasgroup3077]

3/8th wretched drive for E8 won't work at corner of ignation coil male E8 screw (not enough space).

[@Alan318]

What year is your C250? My manual doesn't show what type of plugs to use or even go up to that page number.....

[@carbuying]

2013

[@johnfranco5917]

Are the coils in the firing order 1, 2, 3, 4 as looking at them? Thanks

[@carbuying]

Don't know we made sure however not to change the order they were in.

[@andrynenortey3575]

Hello,I have a 2014 c250.I keep getting misfire in cylinder 3 and 4 when I pack the car for a week or two. I replaced the ignition coils,the low pressure fuel pump,the spark plugs even pulled the injectors out for a brand new ones but The problem never goes away.no misfire in every use.it only happens when parked for long,a week or two

[@carbuying]

How about the spark plug wires? Were the spark plugs gapped properly?

[@andrynenortey3575]

@@carbuying Nope,I sold the car yesterday because I was tired of buying parts to fix an error that won’t go away

[@Redfish-nu9js]

What is the cylinder order from front to back on this engine?

[@carbuying]

Sorry, don't know the order.

[@puuha]

Reading from timing chain towards back of the car sylinder order 1-2-3-4

[@gabrielburgos3178]

Quick question! I too have the same code, P0303, I changed spark plugs, still have the misfire and still have hesitation when accelerating. Would you recommend me replacing the coil packs? Thanks so much!

[@1992teresam]

It’s the ignition coil, I’ve changed all of mine.

[@gabrielburgos3178]

Thanks! I just replaced the coils, car is running perfect now! While I have you, I noticed the check engine is still on. I just changed the coils yesterday, should I wait for the check engine to go away? Or do I have to manually reset it?

[@1992teresam]

@@gabrielburgos3178 I always have to go to my local mechanic who does my oil changes to clear the light for me. It won’t go off on its own. Mercedes will do it too but you gotta pay over 100$! I’m glad ur up and running smooth!

[@carbuying]

If you have your own OBD2 reader and app on phone, you can reset it.

[@SkuuchiMane808]

What's the cylinder firing order ??? I have misfire in #3 any help would be greatly appreciated

[@iammdeepak1]

Do I have to disconnect the battery or disconnect the ignition coil before pulling it out of the cavity? Extremely good video. Thank you

[@mitchio83]

E8 was easy to find at Harbor Freight.

[@carbuying]

Yes, that is where we found the E8. Harbour freight has saved our bacon a few times when we needed rare bits not carried by Home depot

[@altezzar909]

Your owner manual refers to M272 3.0 litre engine not M271 1.8 litre. Are sure it uses the same spark plug?

[@jeffostroff]

When you buy the spark plugs at autozone or whatever store you go to, they look it up by year make model and their computer tells you the correct spark plug.

[@carbuying]

Make sure when you order spark plugs, the stores computer keeps you from ordering new ones, or call your dealer with the VIN# to get the part #.

[@guitartalk4909]

How many miles was on it?

[@carbuying]

About 85,000 miles

[@Rachellray11]

Anybody know how much this cost to get done at the dealership???

[@carbuying]

probably about $200

[@willym1123]

Simple the better and less unnecessary talk ..

[@slah426]

On the paper with spark plug information it’s the wrong c250 it’s the Canada v6 version. The engine here is the 4 cylinder

[@carbuying]

Yes, this is why we stress that you must individually check the fitment for your particular car, most auto parts sites, and Autozone for example when you go into the store, they ask you all about that, and you can compare any suggested part numbers to what they tell you from the computer. On amazon, the auto parts typically have a tool in the listing where you enter your car's info and they tell you if the part is compatible with your car.

[@Bojacksontv]

Anybody have a p0304 before?

[@carbuying]

P0304 is just cylinder #4, same as this error, we usually replace all the spark plugs.

[@Bojacksontv]

carbuyingtipscom i already replaced all Spark plugs & 1 ignition coil? You think it can be compressors or ignition fuel pump at this point

[@carbuying]

@@Bojacksontv what about spark plug wires? I would try that before taking it to a trusted mechanic. It seems like the ECU thinks it can't get a signal to the spark plug. I hope it doe s not actually mean you have a real problem with Cyinder #4! That might be caused by vacuum leak, or your main engine gasket need to be repaired. Hoping it is just the wires. You properly set the gap and measured them on your spark plugs?

[@SlabbyMess]

@@Bojacksontv any luck?

[@passthecash]

you shouldve shown up the part number on the plugs

[@carbuying]

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[@braidontennant]

most spark plugs for your vehicle are already gapped.... not like it's the 80's or 90's

[@carbuying]

They are gapped, but that gap is very critical so it is not set correctly to YOUR car, you will have to adjust it. Statements like yours lack common sense, are completely uninformed, and if stupid people follow it, they will end up with driving problems.

[@capmalogs]

he talk too much

[@carbuying]

You whine too much if you don't want to learn, then go to a fortnite channel. With clowns like you if we cut out parts to make the video shorter then you'll start complaining that we left out this this and this… snowflake

[@laithellabban]

@@carbuying why are you even entertaining this guy