1996 Mazda 626 LX mileage: 70,000. When cold, no problems are apparent. Once at normal operating temperature, it idles erratically and stumbles during normal acceleration, the stumbling is similar to water in the gas or misfiring. It operates well at a constant speed (say highway speed). The "check engine light" has come on. Reviewing the Haynes repair manual, it appears that the problem might be with part of the emissions control systems (oxygen sensor). Haynes has a description of how to get the codes from the OBD by using a jumper wire (between terminals STI and GND) and watching the light to get the number of flashes (i.E. The engine's Morse code). It appears from the diagram of the OBD connector that my car has the OBD-1 system (a group of 25 or so terminals in a compartment under the hood (not an under dash model that seems to be the OBD-II. The directions that they give do not work. Furthermore, in another part of the book they present another example of this same OBD-I connector and give the same terminal (STI) a different name (TEN) that matches the terminal name and position as shown in my car. I am guessing that they have mixed up the diagrams and terminal names. Can you give any information on how to get the codes from the OBD system as a help? I have been told by an auto service provider that the problem with my car is that the oil seals around the spark plugs (o-rings) are shot on the front three cylinders, and that the head cover gasket needs to be replaced, the plugs need to be replaced, and that the special spark plug wires need to be replaced. However, they could not get the codes. I cannot trust them to make the right call if they can't even access the codes (they say they don't have the computer hook-up) and we do not live near a dealer. Your assistance would be greatly appreciated as a second opinion.
Sunday, January 5th, 2020 AT 6:52 PM
(Merged)
