Hello guys, my first post here
So, I've been having issues with P0404 error code on my Hyundai i30 FD, 1.6 CRDi, 66 kW. I've found some old threads that were discussing this issue, but can't find a clear solution to this problem, so I was wondering if someone had the same issue quite recently and managed to fix it.
Pretty much the deal is when outside temperature is above 20 degrees celsius, car tends to go into safe mode or "limp mode" where you have decreased engine power and rev limiter set to 3000 rpm. Sometimes CEL comes on when car gets into safe mode sometimes it doesn't.
What I've tried is to open up the EGR valve and it was absolutely filled with deposits to the point where the valve couldn't even move. I've managed to clean everything up, the valve doesn't seem to be sticking, but even after that P0404 still is coming up.
Went to my mechanic he assures me I need to change EGR, but based to replies from other threads based on this issue, the new EGR didn't fix the issue, since the part itself is quite expensive, would like to try other possible options before going for a new EGR. I belive the EGR cooler is in horrible condition as well if EGR was this bad. Should I try taking the car to the other mechanic to take everything off and properly clean it or maybe there is a different thing I should pay attention to?