Hey everyone first time posting, and I'm desperate. I have a problem with this neon I got from my grandmother.

2002 dodge neon sxt
Got it with 26800 miles currently has 31,000 yes 31k.

Cars in good condition grandma never even drove it on the highway wasn't beat on.

I've done a lot of maintenance since it sat so long. New brakes, rotors, drums, tires, air filter, oil change, spark plugs, wires, new pcv valve. I've sea foamed to clean injectors and I've been slowly inspecting hoses for dry rot for example so far I've done the pcv breather line from the back of the valve cover that goes to the airbox (air filter)

Okay here's my issues.
Car is completely fine when started sometimes I feel like it takes longer than it should to start but I feel I may be used to my old car which was newer.

Once it heats up to normal temperature the cars idle drops to about 600rpm but only in drive and only when I come to a complete stop. When I turn the a/c on it fixes the problem.

Another issue is the car idles really rough in reverse and when I try to reverse up a hill for example the car feels like it's going to stall.

Car is fine in park and neutral although I think the idle could still be a little smoother.

Only engine lights were p0442 and p0455 both Evap leaks one small one large. I changed the gas cap cleared the codes and the large leak came back but unfortunately shortly after the small leak also came back. I'm stumped... I have emissions in two weeks and I can't find the reason for the leaks or idle issues.

I'm most likely going to do a smoke test for the leaks but If someone has any input on both matters I'd greatly appreciate it.

Sorry for so much to read I wanted to give as many details I could.

 

Welcome to the 2nd gen Neon forum.

Lucky you coming by your low mileage ride & kudo's for the maintenance you've done.

We have a "waste spark" ignition system, in which the coil, wires & plugs get worked Twice as hard, as they're fired on Every rotation of the crank shaft. Once on the power stroke & again on the exhaust stroke/waste spark. So, to last, the plugs & wires need to be designed for that double work load.

We also only have two coils to fire 4 plugs, so that means two of the spark plugs get a normal polarity spark that emanates from the center electrode to the ground side wire, the other two companion plugs that share the secondary winding, get a reverse polarity spark that emanates from the ground lug to the center electrode, so double platinum, or fine wire iridium enhanced plugs with platinum pad side wire, will maintain spark gap Much longer than a standard nickel electrode plug, as those metals have a much higher melting point & can tolerate the double work load much longer without spark gap erosion.

I'm running the specified heat range, fine wire iridium enhanced center electrode, with platinum pad side wire design plugs in all my waste spark ignition system rides & have enjoyed quicker year round starts in all.
The fine wire Autolites have been in the Neon 5 years now & spark gap is still in spec. so they're holding up just fine for our drive cycles.

Good idea to have scanned for trouble code clues & posting up the Numbers, as they often help focus a trouble shoot, which you also seem to have a good grip on with the smoke test idea.
If you have a leak in the vapor recovery system, it can mess with fuel trim & if bad enough the IAC might not be able to adjust idle speed enough to compensate.

Not sure yet what to suggest on the tranny reverse anomaly. Have you checked the tranny fluid level & condition, with it on level ground & at operating temp?

How was the vehicle stored, inside a heated garage, or out side in the weather???
Any signs of varmint nests in the air intake inside the inner fender liner. They like to build nests in there & that'll choke off intake air flow.
They also like to chew on plastic & wiring, so maybe they've gotten into the vapor recovery system plumbing?

What kind of device did you use to retrieve the trouble codes, just a code reader, or a scan tool? If a scan tool, can it display live sensor PID's, like the inexpensive ELM scan tool, running software on the viewing device of our choice, that can also query the tranny computer/controller, to see if it's stored some trouble code clues?

Some beginning thoughts for consideration, maybe others will chime in with their inputs. Will be interesting to hear how your trouble shoot goes, so keep us posted.

 

Thank you for all your advice! I recently found a cracked hose off the canister and an actual hole in the plastic shell of the canister. I fixed both and cleared the codes. Car seems to be idling and driving better, especially reverse. I will see if any thing else improves with time. The transmission fluid smells good and is a clear bright red and full. The car was stored in a driveway under a bunch of trees so not the best place. I have checked for rodents and found no evidence. I need to do a coolant flush because I know it's factory coolant. I'm thinking the coolant has lost its ability to properly sustain temperature. Can the coolant be any hoat type or must it be mopar?

Also I used a scan tool. No other codes or clues. Only thing that bothered me was it stated my coolant temperature was 230 degrees F. I think that's a little high.

 

OK, good trouble shooting feedback, find & temporary fix on the vapor recovery system, that seems to have made improvements in engine & tranny shift operation. Maybe a trip to the salvage yard would yield candidates for a permanent fix of the damaged parts & likely at a reasonable cost.
Atta boy, good idea on a cooling system flush. Nothing wrong with Mopar coolant.
I've used Prestone all makes/all models in my Neon & Ford engines for about 10 years/Two 5 year cycles, without any problems so far. Coolant came out as clear as it went in & these rides had aluminum, iron, & a mix of both in the heads/blocks.
EDIT: I use the specified heat range thermostat & a design that has the air by-pass poppet valve design, as it helps burp the system of any entrapped air when we do a cooling system flush.

Disconnecting the battery B- cable to clear the codes & wipe the KAM to clear the vacuum leak corrupt fuel trim tables, also wipes the KAM stored cold & warm idle strategy.
So, after a B- cable disconnect to wipe the KAM, consider performing a cold & warm idle relearn procedure to preclude any drive ability problems & clear the KAM so the computer can begin to rebuild new fuel trim tables.
With the vehicle fully cooled down, All electrical loads turned Off, start the engine & after it idles down, shift into All gears, including "R", ending in "P" & let the engine Fully warm up, without moving the steering wheel, or turning the A/C on, or any other load, until you hear the cooling fan cycle on & off. Then shift into All gears again & that'll have the computer relearn it's cold & warm idle strategy & begin to build new uncorrupted fuel trim tables.