My wife's 2005 neon SE seems to have a misfire and a lot of vibration while driving.

I have replaced upper and lower torque struts, auto transmission mount, plugs, wires, coil and fuel injectors. Could it be fuel filter/regulator, timing belt?

While driving down the road it seems to miss the most from about 40 mph on. The vibration while driving changes pitch as we go over dips in the road. Maybe a CV joint problem.

Any help would be appreciated, I do not want to have to take it to a shop to have them find the problem.

 

If the upper and lower torque struts were bad, it's likely the motor mount went bad and is causing vibration problems. As for the misfire, if the car really was misfiring, it'd very likely have a code/CEL for it. What's it doing exactly?

 

When we drive the car it seems to miss as the transmission shifts. It appears to be worse from 50 mph one. It has never given a misfire code, but it vibrates bad and seems to miss. Could it be a transmission issue?

 

If it's an issue that you notice when the car is shifting, I'd lean towards something transmission related. If the engine is truly misfiring, you'll notice it all of the time, especially when you are giving it a good amount of throttle. When was the last time the fluid and filter were replaced in the transmission?