I know this is grasping straws in a haystack, but I have a 2007 Ram w/V6. Has run like a champ since Day One. This morning, my wife reports that the orange CEL has come on.

Not being as familiar with this truck as I am with the car that I drive, I was curious if there are any 'normal' occurences that cause this (in my car, the O2 sensor is notorious for going out after hitting a big bump. Replace it, reset light and your done).

My issue is, I have neither a service manual for this truck, nor a diagnostic testor to run the codes, and don't want to go swapping parts in hit-and-miss fashion.

 

You either need to get a tuner or OBD scanner or go to someplace like Autozone and let them scan the truck for codes. Then come back here and post the codes so we can help you out.

 

...and after having the light on for 3 days, it went off and has stayed off. That leads me to think its not an O2 sensor gone bad, but more likely the fact that I need to change the PCV valve? Since the light went off, I've not bothered to pull the code.

 

You need to still pull the codes as they could be residual and help you define any future issues. It usually takes 3 times for something to go wrong before the MIL is flagged. Just because it went off does not mean something still isnt happening. It just means it hasnt happened 3x in a row within a certain time frame.

 

I need to change an O2 sensor and my CEL comes and goes.

 

I FINALLY got around to pulling the codes on my CEL ('07 Ram, 3.7L). Came up with two that seem to be fairly common (P0440 and P0456) one is a 'small leak', one is a 'large leak'. In the past two days, I'm also getting a 'GASCAP' display on the dash, so I'm guessing the big O-ring gasket on the gas cap is fauly and it's probably easier to buy a new cap than to try and replace the gasket.

However, not sure which code may deal with the gas cap. I'm fairly certain there is another issue, as the CEL has been on nearlyl a month before I got the GASCAP message.

What are the common (if any) issues that I should check (and please be specific about where to look for the various components. And, could a plugges PCV valve have any bearing on this?

To this point, the truck has been rock solid, so other than normal maintenance, I haven't had to snoop aroudn.

 

I do not know anything about the V6, but I got both the P0440 and P0456 codes when a hose clamp on one of the hoses to the EVAP canister broke off. I put a new hose clamp on the hose and cleared the codes and they did not come back.

The EVAP canister on my '03 1500 is underneath of the truck near the driver's side.

Here is some more info:
http://www.obd-codes.com/p0440
http://www.obd-codes.com/p0456

 

Thanks, I'm going to replace the fuel cap (its mentioned on both the 0440 and the 0456 codes), as well as trace the various vacuum lines on the drivers side near the fuel inlet. I have reason to beleive they may have been disturbed.