My o3 neon Has some issues idling, but its intermittent.

At times it idles smoothly around 750 to rpm and other times its down as low as rpm.

just the other day the check engine light came on with code PO441. i know it has something to do with emissions.

If replacing the gas cap does not fix it what else could be causing the rough idle and check engine light?

 

gas cap? unlikely

possible causes?
-Intermittent condition
-EVAP purge Solenoid Leaks/Stuck Open
-EVAP Purge Solenoid Stuck Closed
-EVAP Purge Solenoid Vacuum Supply
-EVAP Purge Hose Solenoid - to - Canister
-EVAP Purge Hose Canister - to - Fuel Tank
-EVAP Canister

whens the last time you had any ignition service?
clean out the throttle body and Idle Air Control port?
Air filter dirty?

 

The Air filter is clean.
I am pretty sure it needs a tune up, not sure when the last one was done.

I said gas caps because i was looking at some of the other posts on this site and they said that 90% of the time its the gas cap.

The engine also seems to jurk around quite a bit. the motor mounts on the belt side of the motor have been replace not to long ago so there is no damage to those. the jerking is probably just a result of the rough idle.

it does not have any lag in acceleration and does not feel or sound strange at highway speeds.

 

Everyone seems to think it's a gas cap whenever an emissions code comes up; not sure why that is an acceptable thought/reasoning process. Could be a vacuum leak. Could be the NVLD. <--- That's why I keep getting P0441. Nothing else is wrong on my car.

 

I was skeptical on the gas caps theory. When i had my Honda it had a emissions code so the dealer said to replace the cap and nothing happened. it ended up being a fuel tank pressure sensor.

So would the NVLD cause the rough idle?

And a new development is a belt squeal. the belt is maybe a month old and it only happens when first accelerating.

 

The NVLD wouldn't, no. If the idle is rough, it sounds like something needs cleaning or adjustment.

 

there are times when a gas cap will cure an emissions code , unfortunatley its not for this code.

as for the belt, probably just needs to be snugged up, If the belt is a goodyear gatorback brand get used to the squeal. My opinion : only buy Gates belts.
my reccomendation get a tuneup done as the EVAP system rarely causes any driveability problems

 

I've had Gatorback belts on my Neon for a couple of years now and I haven't heard a peep from them. Doubt it's the belt itself.

 

goodyear belts goodyear tires = all junk

 

Meh...