My vehicle: 2001 Neon SE with automatic

My symptoms:
1) extra-rough idle
2) engine killing while stopped with brakes on, in drive.


My codes:
P0303 - cylinder #3 misfire
P0171 - fuel lean

My trial fixes:
new plugs/wires
new coil pack
cleaned intake thoroughly
removed/cleaned/replaced all 4 fuel injectors

Thinking I had a bad injector on cylinder #3, I swapped injectors #3 and #4. This would/should give me a new code for a cylinder #4 misfire but did not. I am still getting a P0303 code, but not the P0171 code that I was getting earlier. What else could be causing this problem with my 3rd cylinder??

 

What plugs/wires/coil pack do you have? There have been issues with certain brands.

 

Sounds like you have a circuit problem on the #3 injector or mechanical issue.

 

I used Champion standard plugs, Bosch wires, not sure on the Coil.

So I may have a bad electrical connection on injector # 3, or maybe my 3rd cylinder is bad?

 

I wish I could help you but I have the same problem with my 94 Neon. P0303 code with rough idle, but it is not constant. When I drive it there is no problem but when my daughter drives it the check engine light comes on and idles very rough.
I was going to get a new coil tomorrow but after reading your post I am not sure what to do.
Has anyone on this board every fixed this problem?

 

Can't remember how to test the coil, but you may try to find the procedure to do so and see what comes up. You may want to test the wires too. They are new, but can be DOA.

 

I found this technical service bulletin

SUBJECT:
Flash: Idle fluctuation and or MIL Illumination Diagnostic Trouble Codes P0300, P0301,P0302, P0303 or P0304

You can see it at
http://www.ertyu.org/steven_nikkel/n.../18-024-04.pdf

It looks like the PCM may need reprogramming.

 

i had problem like that with my 98 neon,but with cylinder #1. a new coil pack fixed the problem i was having with it dieing while i was driving it, but my misfire was due to a burnt exhaust valve

 

My brother is having a similar issue with his ride all of a sudden. Wasn't getting codes till I changed the plugs (which were needed). Then had battery corrosion out the wazooo. I then pulled codes P0301 and P1684. I did swap the coils and got the same codes. How to do you get to the injectors for swapping? Is there anything else that may be a quick check?

 

Mine turned out to be a burnt valve. I bought a cylinder compression test kit from Harbor Freight for $20 and the 3rd cylinder had half the pressure of the other 3.