Hello .
It has been the third time now that i have the same problem on my octavia mk3 2015 1.6 mpi. When i start the car i notice a shaking and right after, the Engine Check Light starts to blink and than the EPC light in on. The car is running rough while driving and in idle. The first time the problem begin i went to the dealer and they said that the quality of the petrol was the cause. They reset the computer and the car was running fine. This was some months ago.  4 days ago when i started the car the engine light come on and the EPC after that. The car was shaking. Went to skoda and they clean the spark plug and said that one spark was working in dry. The cause they said was the petrol that is not clean. I had fill to the top with petrol and the car was running fine. 2 Days i haven't use the car and today when i started it the lights come  on again and the car was shaking. Same as the other times. I don't know what to do. The dealer said is the petrol fault, but i don't think is the petrol as i have changed it  and top it up with other petrol from another company. Do you guys have any idea what's causing the engine light and EPC come on and the car is shaking?

Thank you.

Is it common where you are to have bad quality petrol in some places?

You really need to fetch the trouble codes from your computer to have any way to accurately begin a diagnosis.

Have you done a quick visual inspection to make sure there are no hose or cable connections that are damaged or improperly connected? Probably not that, but makes sense to check the easy stuff until more information is available.

All afternoon today i was under the bonnet and everything seems fine. All the connectors where in place, i didn't see any crack in the intake manifold to get a lean air mixture or something that doesn't seem right. Tomorrow i'll sent the car at skoda and see whats causing the problem. Is it really bad petrol or something else like a sensor.

Well, in my part of the world it wouldn't be petrol. Sensor or some mechanical gremlin is probably it.

Ask them to tell you what fault codes and such they found, get a printout if you can. At least then you'd know if they don't fix it.

Hello again. I just came back from skoda. They checked the engine and they concluded that one of the injectors was blocked from poor quality petrol. The computer showed a code that one cylinder was misfiring and that the engine had run with 3 cylinders, the cylinder that was misfiring had run in dry conditions because of the blocked injector.  They changed the blocked injector with a new one, luckily the car is under warranty. So this is all. On the way home the car was fine and the engine was running very smooth as it should be.  I hope that now the car will be fine and won't have any other problems. 

Wow, that's something. Be careful who you go to for your fuel in future I guess.

Any idea what it is that makes the fuel bad?

Yes. The fuel is bad because i live in Albania. And the corruption level here is very high in all aspects of life. There's no control in gas stations for quality even on big names as gulf etc. By the way. It was the gulf petrol that caused the problem.  Albania has the highest price  for gas and the worst quality in europe. 

That's really annoying. I hope things get better there somehow.

Anyway, glad you got things sorted for now.

21 hours ago, besian said:

All afternoon today i was under the bonnet and everything seems fine. All the connectors where in place, i didn't see any crack in the intake manifold to get a lean air mixture or something that doesn't seem right. Tomorrow i'll sent the car at skoda and see whats causing the problem. Is it really bad petrol or something else like a sensor.

Did they check the fuel filter?

 

If the fuel was bad enough to bock an injector then there should be something trapped in the fuel filter too.

The fuel filter should have prevented contaminants reaching the injectors. Also strange that only one injector was blocked/faulty if fuel was bad.

Edited 11 October, 20178 yr by Orville

The car doesn't have a fuel filter as long as i know. Only air and oil filter. 

@besian - I could be wrong, but most fuel injection cars have at least one fuel filter between tank and engine. You're probably looking for something made from clear plastic and a little smaller than your fist, near the tank or tucked up in the raised area of the floorpan.

3 minutes ago, KenONeill said:

@besian - I could be wrong, but most fuel injection cars have at least one fuel filter between tank and engine. You're probably looking for something made from clear plastic and a little smaller than your fist, near the tank or tucked up in the raised area of the floorpan.

I don't know if there is a fuel filter in that place but under the hood there isn't any. I will check this as soon as possible.  Anyway, i hope that the blocked injector was causing the problem and that the car will run fine from now on. Thank you all for your suggestions.

They seem to be going for lifetime filters these days on many models. In places with poor quality fuel, maybe lifetime is a little optimistic. That said, everything last's its own lifetime....

 

On many cars it is located near the fuel tank, not far from the right rear jacking point. It is very often a silver cylinder about 10 cm by 8 cm diameter, or it can be clear plastic. Either way they have two or three pipes going into them and are pretty easy to change if they need changing.

Edited 11 October, 20178 yr by LightRain
Because I'm a dope....