Toyota Celica 2005 Ecl Lift Valve

[LazyBear]

Hi, I bought a used celica 2005 100,000miles with full service history with 1 owner and the car looked very well. It drives very nicely as well and ive had no issues but the enginge check light came on and after taking it to the garage the code that shows up is from the lift valve(P1349). It got reset and it came back on after 600 miles. During that time the car felt exactly the same and drive flawless without any weird noises or hiccups on every gear. I was advised that i shouldnt worry about it and i can keep driving it without doing any more damage( if there is any done) but the light will probably come back and stay on. Has anyone had experience with this and got it fixed? I looked around the internet and there is a lot of talk about lift bolts and oil pressure causing the issue but how to do pinpoint the problem? Will it be costly to be diagnosed at toyota itself? Should i even be looking to fix the issue if it doesnt affect the car and could cost a lot? Thank you.

[Old Red Celica]

Oil Control Valve filter getting blocked?

[LazyBear]

After some research and talking to the previous owner( who said that he had it inspected at toyota and the light went away on its own soon after) i am guessing this is the issue. is this a good guide to follow to clean it?
http://www.celicahobby.com/forums/ubbthreads.php/topics/359434/vvti-fluid-control-valve-filter-gts-how-to-clean.html
If it turns out this is the case, how do i avoid this in the future? The car has been serviced every 10000 miles and the oil is very clean and up to the mark. Should i use different type of oil or is something else causing it?