Hi everyone,

For about the past month, I've been experiencing an intermittent and unexplained loss of power on my car. There are no warning lights, no check engine light, and no fault codes stored. The car simply feels down on power, almost as if it's lost around 10–20 kW. When it's running normally, the turbo builds boost early and the car pulls well. During these episodes, however, boost seems to come in much later at higher RPM, making the car feel sluggish. I've also noticed a significant increase in fuel consumption.

Under normal conditions, I average around 4.7–5.3 L/100 km, but when the problem occurs, it rises to about 6.0 L.

So far I've found and repaired a broken EVAP hose, and the engine ECU has also been updated with the latest software, but neither has solved the issue. I also checked intake valves for carbon buildup - they are clean.

The strange part is that the problem is completely intermittent. It doesn't seem to depend on outside temperature or driving conditions. For example, during a recent road trip, the car drove normally for about 200 km, then suddenly became noticeably down on power. After driving for a while longer, it returned to normal on its own. Today it became sluggish again.

Has anyone experienced something similar or have any ideas what could cause this, especially when there are no fault codes?

What country are you in? Is the ECU Software update because of a TPI / TSB from Skoda? What ambient temperatures are you talking about where you are? When were the spark plugs inspected or replaced? Is there a fresh clean air filter fitted? What is the fuel used, E5 or E10?

Edited 4 hours ago4 hr by Evolution13

3 minutes ago, Evolution13 said:

What country are you in? Is the ECU Software update because of a TPI / TSB from Skoda? What ambient temperatures are you talking about where you are? When were the spark plugs inspected or replaced? Is there a fresh clean air filter fitted? What is the fuel used, E5 or E10?

I'm in Slovakia.

The ECU software update was performed by the dealer, but I'm not sure if it was related to a specific TPI/TSB.

Ambient temperatures have ranged from around 15°C up to 40°C, and the issue has occurred in both cool and hot weather.

The spark plugs and air filter were both replaced about two weeks ago, and I always use E10 fuel.

Maybe try some E5. Lots of rubbish fuel about since the 'Military Action' in Iran. Everyone will be looking for Software Updates now. I Love 'Skoda Secret Service Service Campaigns'.

Just now, Evolution13 said:

Maybe try some E5. Lots of rubbish fuel about since the 'Military Action' in Iran. Everyone will be looking for Software Updates now. I Love 'Skoda Secret Service Service Campaigns'.

Thanks! That's actually my next step. I'll run a few tanks of E5 and see if it makes any difference. Hopefully it's something as simple as poor fuel quality.