I have a 1993 Mercury Sable 3.8 liter V-6 auto transmission with about 106,000 miles on it. The check engine light came on while coasting down hill around 35-55 mph. but went off right when i gave it gas. So when I got home I put the EEC-IV Diagnostic Trouble code check on it and got a trouble code 157 Manifold Air Flow Sensor Fault (Low Voltage) and 628 Excessive Converter Clutch Slippage. So I purchased a new MAF Sensor and put it on and the car ran well didn't have a rough idle had power and ran well. Now about five days later i was going down a fairly long hill coasting 45 mph and check engine light came on then right when i gave it gas it went off. So I tested it again and got the same codes. Now i'm puzzled I don't know what to do. If any one has any information at all for me it would be greatly appreciated.
Thanks alot.
Mike

 

Hey mjm4310.
Make sure all the hoses and clamps are in good shape. It sounds like the motor is sucking air that should be going through the mas air sensor insted. check for bad vacume lines a hole in the air intake hose etc. Just a thought.