2002 Lexus RX 300 - upper plenum gouges

upper plenum flat surface has gouges on lexus rx300 2002

I presume you’re talking about the intake manifold gasket. I couldn’t say why it might have gouges but your best bet is to replace it. If this is a part you just bought, take it back and ask to see another.

Yes I think I damage the flat side with a screwdriver or a bar to pry up the upper pelunm and saw the gouge marks and of course later on my CEL, VSC trac light
stayed on

That part has nothing to do with the VSC system. Your best bet is to have a good independent shop look at the vehicle. VSC problems can be dangerous under the wrong circumstances.

When there is an active fault detected by the PCM, the VSC system will be disabled. Don’t worry, you won’t slide off the road.

Repair the vacuum leak and erase the engine fault, both warning lights will go out.

The mechanic showed me scratches and gouge marks on the gasket side of the upper pelunm. Mention it has to be replace for a good seal.