Service diagnostic of my Honda Civic (manufacturing year - 2000) ECU showed the error 30-1. It seems to be the CVT error.
Does there anybody know, what this error means?
Could it be because of old dirty oil in CVT? The car was driven over 80.000 km, and oil has never changed.

I don't know about the error code, but I can tell you that forgeting to change the oil can have devastating effects on the engine.

Oil gets turned to some black gunky sticky material over time (when used) and that can clog your oil passages in the engine. I can happen that oil passages get so clogged that oil cannot reach the engine head no more and lack of lubrication in an engine is NOT a good thing.

Anyway, I'm sorry I don't have any more information about your error code, but I just wanted to point out how bad of an idea it is not to change your oil.

2 CroCivic91
Thank's a lot. That's for sure, the oil must be changed and will be.
I hope, that the CVT is still in good condition.
It's so expensive part...

p1607