I have a 2002 Elantra GLS MTX 2.0 with around 85k miles on it. The car's been reliable overall with just one minor repair, a recall on the brake lines. It's had regular maintenance, and the timing belt was replaced about 20k miles ago. About three weeks ago I got CEL P0441 (EVAP Emission Control System Purge Flow Fault). Knowing that this can be caused by the gas cap being loose, and wanting to try the easy things first, I removed/tightened the cap and reset the code. The car was good for a couple days and then threw another CEL. When I rechecked them we got the P0441 again, as well as P0340 (Camshaft position sensor A - Bank 1 circuit malfunction). Aside from the codes the car works fine.

We went ahead and had it diagnosed by the dealer with them wanting to:
-replace the camshaft sensor
-replace the crankshaft sensor
-replace the Purge Control Valve

All this to the tune of $200 in parts and $300 in labor. I checked and I could get the parts online for about $157 but not knowing where the parts are and what's involved in their replacement I'm not sure if they're repairs I can do myself. I wouldn't say I'm a mechanic, but I've done starter/alternator replacements, brakes, tune ups, fluid changes, etc. so as long as it doesn't involve lots of specialised tools or drastic disassembly of the engine I should be okay. The only thing I really found on the forum about this were on 2.0 Sonatas where replacing the crankshaft sensor apparently requires removing belts and a pully.... that's a little beyond me. I searched around (both on the forum, and the internet in general) and found several other people with the same problem on their Elantras. Many of them said they replaced the cam/crankshaft sensors but still had the CEL.

So, can anyone help me out with:
-Where the components are located?
-How involved is the replacement of them?
-Is it necessary to replace all of them at once or trouble shoot?

To cap it all off this happened right as our car's inspection and re-registration is coming due..... literally in less than two weeks. The car can't pass inspection with a CEL on (or within 100 miles of having one on), and the registration can't be renewed unless it's inspected. Basically I'm in a bit of a time crunch so any help anyone can give would be welcome.

After a little more digging I found that the PCV is located on the back of the engine near the throttle body, and the Camshaft sensor is on the back right of the engine. Sadly the crankshaft sensor is as difficult to get to as it is on the Sonatas.

Additional question. Could a faulty PCV cause the errors with the camshaft sensor?

The crankshaft sensor is located on the right rear side of the block about 3-4 inches below the cyl. head. Is very easy to change and looks very simalar to the cam sensor except the wires come out the top of the crank sensor. Its is next to the oil pressure sensor. Look just to the rear of the shield on the exhaust manifold. One ten MM bolt and some penetrating oil and work it back and forth while pulling it out. You may find the leads to the sensor are cracked and bare in places.

Are you sure you don't have those backwards? The info I found on hmaservice.com showed the camsensor in that location, not the crank sensor. I haven't inspected it yet, but if the leads are exposed could that likely be a problem vs. the sensor itself being bad?

The camshaft sensor is located on the back of the cyl head, above and to the right of the crank sensor. Think about it, where is the crankshaft located and where is the camshaft?

I went through the electrical troubleshooting from hmaservice for the camshaft sensor yesterday and everything checked out. I replaced the purge valve yesterday, and ordered a TDC sensor (apparently what the camshaft sensor is called by Hyundai) which should be in today. After the purge valve was replaced the CEL went off (though the PCM had to be disconnected for the troubleshooting). I've had about six or seven drive cycles with over 80 miles total on the car and so far no new CELs.

I've heard that when the Crank sensor or the cam sensor go bad, it's a good idea to replace both of them at the same time. In this case, it's pretty easy to change both of them. The crank sensor is the engine block behind the crank pulley, so you don't have to remove the timing belt. I like that, $200 for parts and $300 for installation. These parts can all be replaced in a few minutes. I'd say 30 minutes is fair.

Good to know. Can you provide any more details on where on the engine block that is and how to replace it? hmaservice and diagrams for both the camshaft sensor and purge valve, but nothing for the crankshaft sensor.

Update. I replaced the PCSV and camshaft sensor, ran for three days without a CEL, got the car inspected and the registration renewed......... then I got another CEL. This one is P0139 (O2 Sensor CKT Slow response (bank 1 sensor 2)). The car is still running fine. The only thing that's changed is those two parts were replaced and the serpentine belt was retentioned (was squeaking). When I replaced the purge valve all of the hoses were in good condition and I got all the hose clamps back on tightly so I don't know if that could be causing the o2 sensor code.

Any other thoughts on the cause of that one? Also how to know which o2 sensor is causing the problem. hmaservice seemed less definitive on that code.

Looking back at your post it makes perfect sense. For some reason when I first read it I thought you said the crankshaft sensor was on the rear right, vs. the right rear. My bad, and thanks for the help.

So just looking at the engine in the dark there are several harnesses plugged into things in that area and I'm not sure which is which. If it would help I could post a picture and someone could point out where it is.