HEY GUYS, NEW HERE.
I JUST BOUGHT AN 04 PACIFICA AND HAVE PROBLEMS ALREADY. IT'S MINOR I THINK BUT I WAS WONDERING IFYOU COULD HELP. IT HAS A MIDRANGE BUCKING FEELING. AROUND 3000RPM. MOST NOTICABLE UNDER LOAD JUST AFTER DOWNSHIFT FROM O/D. I SCANNED AND IT GAVE A P0700 (TRANS FAULT) AND P0562 (LOW VOLTAGE). I THINK IT WAS P0562. IT DID SAY LOW VOLTAGE. THE CHECK ENG LIGHT WAS NEVER ON AND THE BATTERY WAS DEAD WHEN I BOUGHT IT, DEALER GAVE ME A NEW ONE. I CLEARED THE CODES AND TOOK IT TO A FRIEND WITH A TRANS SHOP A WEEK LATER. STILL NO CODES BUT IT HAS THE BUCKING FEELING. HE SAYS IT'S NOT THE TRANS OR TCC. HE THINKS IT THE ENGINE, MAYBE A MASS AIR SENSOR OR EGR.I HAVE NO HISTORY ON CAR, BUT I CHANGED THE TRANS FILTER AND FLUID. THE PAN WAS VERY CLEAN WITH VERY LITTLE FUZZ ON MAGNET. IT HAS 60K.
ANY IDEAS, I'M HEADING ON A LONG TRIP NEXT FRIDAY.
THANKS.

 

With 60k on the clock it may not be a bad idea to check the air filter and maybe change the plugs. The plugs from what I hear can be a bit of a bear but probably worth the effort. Have you run any fuel system cleaner through it also? That also might be a good place to start. How long has this been going on? Have you refueled the car yet since this started happening? May be some bad gas.

P.S. Is you car certified?

Keep us posted,

Bob

 

Could it be the throttle position sensor?

 

I know im digging from the grave here but i'm having the same issue. Did you resolve this? Any help would be beyond appreciated