Mazda Repair: mazda 626 eng. light, exhaust gas analyzer, o2 sensors

Question
hello. My check engine light came on so the mechanic replaced 2 new o2 sensors. light went off. 100 miles later, comes back on, then 15 miles later, the light starts blinking, and the engine starts missing and or knocking. took it straight home because i live in the boonies and didnt want to get stranded. I cant find anything wrong. Could it be the catalitic converter is bad? help!

Answer
Well, without seeing the car in this case it is hard to know what could be the cause. I suspect a bad coil pack and or a toasted igniter but that is beside the point without seeing the car. Call the mechanics and tell him it quit and is unhappy and get it towed into the shop. That is about the best that can be done at this point and conjecturing on what if is irrelevant without solid symptoms on what is what in this case.

The mechanic will have to use a stand alone Exhaust Gas Analyzer to diagnose this problem and find the exact reason why the ECM is dropping out fuel and advancing the hell out of the ignition. Since sun tuners and other stand alone units cost in the vicinity of $12k - $19K depending on goodies I am not going to expect you to run out and get one so we can root the problem out ourselves.

I have had all kinds of problems that started out this way and turned out to be something so off the wall that I have classified the returning CEL with 02 sensors involved as an in person only diagnostic.

Wish there was more that could be done,

Regards,


John