This is most noticeable at highway speeds, although can feel it at lower as well. With steady gas given, car pulls and releases every couple of seconds. Check engine light came on and got the codes 3-4-3-5-5, although there was a slight pause after the first blink, so could possibly be 1-2-4-3-5-5? Anyone know what a bad speed sensor would do? I also take very good care of the general maintenance on the car, recently changing plugs, fuel filter, air filter, and cleaning injectors.
Thanks in advance.
G

 

12 Direct battery input to PCM was disconnected within the last 50 key-on cycles

43 Multiple/ single cylinder misfire
55 end codes
it could be in your coil pack, if you just changed your spark plugs its probably not that but dont rule it out. or even a little water in the gas.

 

That would depend on what type of plugs he used. If he used platinum or split-fire, thats a NO-NO!