1996 Dodge neon 2 litre sohc.

Runs rough when cold but better after warm up. Seems to lack power at higher speeds. Have changed the wires, plugs and O2 sensor.
Any ideas?

JayJay

 

First question would be, is the CEL lit?

Second, does your '96 have the plastic or aluminum tank? If it's aluminum, then you have an external fuel filter that's supposed to be replaced every 30k miles. Could be an issue...

Third, what plugs and wires? Platinums suck, coppers are great. Stock wires are fine, gimmick wires (Nology, for example) have had serious issues.

Fourth, which O2 sensor, and why? If there was a code for a particular sensor, I can see replacing it. The downstream sensor on the '96 does have input to the fuel trim calculation, but it's rare for it to be that bad and not throw a code. And if your new sensor is by Bosch, you could have issues (factory is NGK, or whatever name they go by for sensors...). My car ran richer after replacing it with a Bosch sensor, emissions got worse as well... I'm not the only one that's had the problem, I just didnt' listen to guys more knowledgeable than I when I did it... lesson learned...

What types of speeds are we talking about?

What tranny do you have?

 

Thanks for the Reply Jeremy,
I was repeating what my son in law told me as it it his car. It is too cold up here to try anything for awhile. -25C today with windchillof -35 so I guess it will wait till spring. He did say he changed the rear O2 sensor on a tip from a friend because his gas milage was poor. He changed his own plugs and wires so I don't know what he used. The on board diagnostics showed a code 43 and he said his no 4 plug was wet when he pulled them. Other than that It will have to wait till spring.

thanks,

JayJay