'95 Neon problem

Hi guys,
The problem I am having is my car starts to chug,almost seems like a miss after 20 mins. of driving.
The thing I have replaced or checked is so far:
New O2's
tried injector rail off old engine
new fuel filter
plugs and wires
changed coils
checked fuel pressure when driving and idle(50 psi)all the time
tried swapping throttle bodies.
The primary circut code has come up a few times but now there is no codes.
After changing all this stuff it still run the same.20 mins of driving it starts to act up.Anyone else have this problem?
Thanks for the help in advance,
Trev

You did the key dance top pull the codes right?

Not sure what you mean by that?
Trev

Not sure what you mean by that?
TrevThe key dance, where you turn the ignition switch to on-off-on-off-on within 5 seconds to read the codes. If you don't know how to do it, search this forum using key dance as your search and it will pull it up in a few threads.

I have a code reader.Also friend has the Snap-on one.There is no current codes.It still surges after about 20-30 mins of steady hwy cruising.Then it does it all the time till you shut it off and let it cool down for awhile.Could this be a EGR issue or C.Converter?Not sure just trying to figure this out,because there is no codes?
Thanks,
Trev

A faulty EGR can cause problems if it isn't working properly. Have you checked your coolant level or thermostat? Are you sure it isn't overheating?

The coolant level is ok.It is a new rad,when it put the motor in.The gauge in the car has always been in the center of the range.
Das-does the EGR work right away(on a cold engine)or does it take 20 mins or so to start working.Is there anyway to check this or bypass it.A friend of mine is bring the Dodge computer home this weekend,so hopefully we can record this when it is happening and he can look it up on Mon.
Thanks for your help Das,
Trev

does the EGR work right away(on a cold engine)or does it take 20 mins or so to start working.it starts working right away. you can take it off ans see if the valve moves when you blow into it. you could also block it off and see if the car still stalls on you.

The engine light came on this morning on my way to work.Tonight when i got home i did the key dance and it came up 12 and 43.Then I checked with my OBD-2 code reader and it came up with P0351.Which is the primary circut again.This is the 3rd time this code has come up.The plug into the coil has been checked for pulled wires,the coil has been changed 3 times it also has new plugs and wires.Any ideas what else I can do?It seems like a miss fire after it is warmed up.
Thanks,
Trev

What kind of plugs did you use? If they are platinum, junk them and get the stock champion plugs. Also check the wiring and connections leading up to the coil pack.

I am using Champion plugs they are new.I checked the wiring by looking at it and using an ohmmeter.If it was a wiring issue would it do it all the time?
Trev

If it was a wiring issue would it do it all the time?
TrevCould be all the time or intermittently.