Hey there,
I got a 2000 neon which has been giving me some issues with an intermittent p0340. The problem started happening about 4 days after I replaced the timing belt. I don't think they are related, considering when the check engine light is off, the engine runs perfectly fine... no loss of power, no roughness. For the most part, the light will come on for a day or so, turn itself off for another day or so, come back on again and so on.
It has never had trouble starting, but it has stalled out a couple of times (when the light is on, of course.)

Now I did take somewhat of a look at it..
With the sensor unplugged, KOEO:
8.99V @ Source
5.01V @ Signal
Good ground.
Am I supposed to see 5V at my signal with sensor unplugged? Or do I have a short to voltage?

I have also noticed there is an oil leak, guessing from the cam seal, because there is a decent amount of oil all around the sensor... Could this be my issue?

I have also heard that the crank sensor can trip this code in some cases... Is that true?

Thanks for the help.

 

the oiled up sensor could definetly be the issue.
and yes an intermittent crank sensor can cause this too.

from what you've tested so far I'd say wiring is fine
8+ on source? check
5V on signal? check
Ground? check

yes u should see 5V when it's unplugged. any more than 5V would be short to voltage

you probably dont have a DRBIII but ther are some checks here you can do with just a plain old multimeter
http://i53.tinypic.com/ibxb3m.jpg