Car not running 02 neon automatic SXT. Alright it started with a idle studder when at red lights or just idling in drive or park. . Then it moves to not wanting to start and just turning over and over. It did always end up starting. I left it running while I ran in to the store and it threw a check engine light finally p0171. Next day fiance decided he's going to take off the maf sensor and clean it. Well there isn't a maf sensor and he cleaned the IAC thinking it was the maf. Anyways now the car still don't want to start but is completely not able to be driven. When you hit the gas it hesitates so bad and bogs down. So I'd assume I need a new IAC because it got worse when he messed with it. But would anyone help me assume if that was my original problem? Or did he cause a complete new problem? I drive for my job and really need my car. I need the job to buy car parts lol. I have a new IAC on the way but won't be here till earliest Wednesday.

 

Changed out the iac and it didn't change anything. 02 sensors are reading good.

 

You may have a very dirty fuel filter. Has it ever been replaced?

 

I have no clue. Someone told my fiance there isn't a fuel filter.
edit to add: I haven't replaced it I have only owned it like 6 months. I see there's like a little filter on the bottom of the fuel pump but advance was saying u can't just buy that u need to replace the whole thing

 

It has a fuel filter. It's inside the fuel pressure regulator/filter assembly that mounts to the top of the fuel pump. It can be replaced without lowering the fuel tank. You can download the factory Neon repair manual for free to see where everything is located, how to test stuff and replace it. My son gave me his '05 Neon a year ago so downloaded that so I can try repairing things myself before getting professional help.

That P0171 code means that O2 sensor is detecting too much air in the exhaust. Since your car went from running bad to worse without throwing any other codes (there's codes for too high/too low fuel pressure), you just may have a vacuum leak in a vacuum line, the PVC hose or a bad/loose gas cap.
The fuel pump also has a relay that sends current to the fuel pump. I'm not sure if a code is thrown when the relay starts acting up then goes out for good. It'll be inside the fuse box under the hood. There may/should be another relay just like it for something else next to it. Those usually send power to something you can do without for awhile, like door courtesy lamps and seat belt chimes. You can swap those out to test the fuel pump relay.

 

I have looked for vacuum leaks but I'm going to go try and look some more today. I can head the fuel pump run when I click the key on. I've had so many idea thrown at me the past few days now broke lol. So I'm going to go down a free route today. Thank you. I'm really wondering if I could of clogged my filter bc i didn't know but the fiance ran i super low most empty the day before all this started happening. But not sure if junk got in there if I would of started being terrible that day. Anyways I really appreciate the knowledge.

 

How many miles are shown on the OD? Did it come with the owner's manual that kept in the glove box? It has scheduled maintenance pages in the back that show what should be done after every X number of miles so may lucky to see where previous owners did those by checking the boxes and writing the date w/mileage on the page. Looked mine over to find there's no scheduled replacement for the fuel filter.

Since your car will start and run, hen you'll be able to check the fuel pressure and delivery by removing the fuel line from the injector rail. The fuel system is pressurized so is depressurized by removing the fuel pump relay before starting the engine. The engine will run until the pressure is too low to push gas thru the injectors. The fuel line should be holding a pressure of 50 - 58 PSI when running with a check valve in the fuel pump keeping pressure in the fuel line after the engine is turned off. The engine should start and run like it's running out of gas if the line still holding some pressure. It won't start if the pressure is low. Now you can remove the fuel line from the injector rail and reset the fuel pump relay. Stick the end of the fuel line into something like clean 2 liter pop bottle and have someone turn the key to ON to see how much gas comes out in 15 seconds to 30 seconds. A good fuel pump should push out from 3/4 to 1 quart of gas in 30 seconds. Less than that may indicate a clogged fuel filter, dirty fuel inlet sock, defective fuel pressure regulator or a weak fuel pump.

Hopefully you'll find a vacuum leak in a rubber/plastic line. The EVAP system has it's purge solenoid down low in front near the steering gear with a vac line at the bottom and one at the top with the solenoid valve in the middle. That valve stays closed at idle and will make the engine run crummy at idle if open. The top line runs to the intake manifold so.you could remove it from that connection to see if there's any change in the engine's idle. .

 

It's got like 250 I think getting closer to the 300 mark. I have the manual but nothings in it. I have a sneaking suspicion not much has been replaced unless it had to be. The struts are insanely bad along with the rotor completely half gone and no brakes on the drives side, horrible axels and super bald tires when I got it. It sat in a field for a year or so after the last person got it and never drove it There was a new oil change sticker within a not so bad milage tho. The cars red and they spray painted it black and white all over he dash in sharpie I'm assuming teens and a lot of weed stems ect. It's a beater car but it's all I could afford and ran decent for the price. But anyways. Awesome thank you for that give me another step to go to. I haven't had a ride to get a fuel pressure gauge. I did order the regulator and a fuel pump incase. It's super hard to get I to start. But it will idle rough to normal sometimes but if you hit the gas or put in in reverse ect it dies or tries to die.

 

Since the engine will start and run, you may want to try adding a fuel system cleaner to the gas tank then allow it to idle for a prolonged period of time so it can work it's magic. The fuel pump assembly and the injectors may be gummed up with deposits made by using cheaper discount gasoline that contain a lower percentage of detergents like top tier gasoline brands. I've been using Berryman's B-12 for that since 1973 due to being cheap and effective. Walmart sells 15 oz. bottles of that for $3 to $4 so one should be enough to overdose a 1.2 full tank of gas to get faster results.
It should have a "newish" fuel pump assembly due to the mileage and be fairly obvious by looking cleaner that the surrounding areas. The engine probably had the timing belt/water pump replaced at least once since that's supposed to be done every 102,000 miles. My '05 Neon had 123,000 miles when given to me and still using the original belt and pump. The engine also shook the car so I bought four new motors mounts along with a timing belt kit since three mounts are removed to gain access to the belt and pump. Newish looking motor mounts may indicate that was done after 200,000 miles.
I suspect it was parked due to front end wear chewing up the tires. Since you have a high mileage beater, you best source for affordable parts will be from a salvage yard. The drive axles, strut assemblies, wheel bearings and brake discs/calipers were probably used on several models over the years so may have some out in the yard or inside on shelves. Those aren't hard to replace if one has a decent set of tools. Have any friends that are gearheads? .

 

I've put all new axels and obviously tires. I got the brakes all fixed. I've had it and been driving it for about 5months or maybe a little longer. It's always run a little rough. I've still got to get struts all 4 or whatevers on the back. Its bouncy lmao. I ain't got no friends at all lol. I can do a decent amount of stuff myself just from growing up with a mechanic plus my ex of 10 yrs was a mechanic and he always made me help n do stuff. So I'm pretty good at changing stuff but the diagnosing part I'm clueless. That's pretty much why I've just been throwing whatever parts ppl have recommended with this issue. It's gotten pretty costly at this point. But not as much as a shop just yet. Plus the bonus of a lot of new parts.lmao. But tomorrow I'm going to try and change the regulator and try some of things mentioned.