it is a 93 ssei 140000 miles. it started to vibrate when it is idling and at low rpm. it has less power and bad gas mileage. puts out a 31,54,and 55 code untill i reset the ecm now it is a 54. the codes i got from this site has no 54 code on the list. what may be the problem? any help would be appreciated.

31 is your P/N switch. It'* not the problem. Nor will it affect how the car runs. 54 is EGR solonoid #2. A thorough cleaning of the EGR valve should fix this (you have the digital EGR, and many of us have seen this, cleaned the valve shafts and return springs, and fixed it).

55 concerns me. That'* a general PCM fault. Try disconnecting your battery for 30 minutes, and re-seat all your PCM connectors (PCM is above the RF passenger footwell). See if the 55 comes back.

Where are you located? Can you put your location in your profile, and put "93 SSEi" in your signature? Both of these will help us to help you.

i think the 55 was from when i plugged the key into the wrong spot on the plug in. i'll try cleaning the egr and posting my info. thanks for the help.

tried to clean up egr but the small screws broke off just like i thoughed they would. tried to drill them out and retap but couldn't go through screws. needless to say i need a new base for the egr. is there a rebuild kit fir it? is there any way i can get around the $200 charge other then junk yards?