Check engine light is on does this generally mean

To remove a PVC (positive crankcase ventilation) valve from a 2004 Dodge 1500, you will need to follow these steps:

1. Locate the PVC valve. It is typically located on the engine, near the throttle body or intake manifold.
2. Disconnect the battery. This is important to ensure safety while working on the vehicle.
3. Remove the PVC valve hose. The PVC valve hose is connected to the engine with a clamp. Use a screwdriver or pliers to loosen the clamp and remove the hose.
4. Unscrew the PVC valve. The PVC valve is held in place with screws or bolts. Use a socket wrench or a screwdriver to remove these fasteners and take out the PVC valve.
5. Install the new PVC valve. Follow the steps in reverse order to install the new PVC valve. Make sure to tighten all the fasteners securely and reconnect the battery before starting the engine.

Note: If you are not familiar with automotive repair or are not comfortable working on your vehicle, it is recommended to have the PVC valve replaced by a professional mechanic.

Injectors, compression, several engine mechanical issues ( burnt valves, weak or broken valve springs, piston rings, head gaskets, cracked block or heads ) and bad ECM drivers for injectors/coil packs can all cause engine misfires. The flashing light means possible catalytic converter damage .

Sorry Darryl I am not conversant with PVC connected to cars. Do you perhaps mean PCV?
Positive crankcase ventilation is sometimes controlled by a valve which should be checked, cleaned or replaced as required during routine maintenance.

The PCV valve is often found screwed into the engine valve cover and is part of the engine breather system which vents foul crankcase emissions either into the air cleaner or into the inlet manifold.

I hope this helps.

The lines going to the PVC are what you would have to remove and check with a Vacuum pump or Vacuum source. Close off one end with your finger and apply Vacuum to the remaining end.
The engine and its cavities produce a Vacuum pressure when the engine is running to draw in vapors from the oil system. Therefore any hose connected directly to the PVC valve will vent through that system so you will need to test the parts off of the engine.
The PVC valve is a cheap part and usually does not break between replacement intervals. Because of the spring valve inside this part, it is to be replaced at intervals just like an air filter.

Don't know about a pvc valve but I know that I had a pvc hose just replaced on mine a couple of months ago. My check engine light was on

REMOVE PVC VALVE WITH VACUUM HOSE STILL ATTACHED CHECK FOR VACUUM AT PVC VALVE PLACING FINGER OVER IT.IF NO VACUUM FROM PVC VALVE BUT THE HOSE TO PVC VALVE HAS VACUUM REPLACE PVC VALVE.IF NO VACUUM GETTING THROUGH PVC HOSE AND VALVE.LOOK FOR DISCONNECTED BROKEN VACUUM HOSE OR OBSTRUCTION IN VACUUM HOSE BLOCKING OFF VACUUM.

pcv valves are generally located on top of the engine's valve cover. A tube made of rubber generally goes to it.

Code P1491 is not the PVC Valve.It is the Vacuum Cut Valve Bypass Valve.
Which is located above and away from the egr canister under the driver side rear bumper it is round and have about 3 hoses connected to it. if it is from a check engine light that says look at vacume cut valve check the egr canisters purge valve some times they stick and throw the wrong code

Make sure your gas cap is tight this will cause the light to come on this is a very common problem
The PVC vale is usually on top of the engine