P0441 and P0340 on Hyudai Elantra

My daughter’s '02 Elantra is having check engine light problems. The codes pulled are p0340 and P0441. The first is a cam angle sensor circuit warning. Probably a bad cam angle sensor.

The dealer wants to replace 2 sensors and the EVAP purge valve. I understand the cam angle sensor, and the purge valve, but I’m wondering what the second sensor is and does anyone have a feel for how many hours this sort of thing ought to take?

Could a decent shade-tree mechanic replace the purge valve himself? How about the cam angle sensor?

I don’t know about the Elantra specifically, but in general these kinds of items should not be too hard to replace yourself.

However, the real question is whether or not they really need to be replaced. Parts get thrown at codes all of the time only to find that new parts don’t fix the problem b/c the problem is elsewhere in the system. So has this dealer actually tested anything - e.g. for proper voltage/signal at the cam sensor harness? Has the wiring been inspected? Checked for continuity? Similarly w/ the evap system. Don’t let anyone just throw parts at it.

The purge valve btw controls the flow of fuel vapor into the intake. Cars these days collect the gas fumes in a recovery system and feed them to the engine to burn rather than just venting to the atmosphere. The purge valve controls the vapor flow.

I’m getting info second hand, so can’t be sure what they have done as diagnostics. From reading the information I could find on the web it seems like the camshaft angle sensor would be pretty easy to check and difficult to replace. So, I’m assuming they did actually test that.

The other code for the EVAP system they did check the gas cap and clear the code, but it came back, so the next most likely is that purge valve. Again, I’m getting this second hand and I really want to know what that other sensor is they want to replace. That does make me wonder if they are shotgunning it.