I recently had a friends scanner tell me my MAP sensor, and O2 sensor were bad, I replaced these items and the service engine soon light went away. At the same time though my car now has a flutter or vibration when I accelerate, but there is no light on. If I buy a Auto Xray will it tell me what is wrong or without a code do I have to find it manually? Does anyone have any ideas to what my problem is? I cant even spin my tires because of this flutter. It seems I have lost alot of power also. No smoke when I get on it, and the engine temp seems normal. Just this huge hesitation. EGR valve?

 

Your OBD-I 1994 PCM does not have the capability of identifying misfires, so its not likely you will get a code for "fluttering"......

The scanner is simply going to give you visibility on what the readings are for a large number of the engine sensors, and the PCM calculated parameters. You need to "interpret" that data to determine if there is a problem, and what the problem is.

I have an online writeup on scanners that will explain some of what you can do with a scanner, and what the data means....

ScanMaster Writeup

Might help, might not.