Chrysler Repair: engine problem:Mazda 626, pollution control systems, 4 digit numbers

Question
Hi
I have a question a 1996 Mazda 626. This car has 187,000 miles but it was running really
good. I change the oil three days ago, since it has high mileage, I purchased a Wal-Mart brand motor oil that was designed for cars with high mileage. It ran on the new oil for
150 miles and now the engine started to run rough. I drove it home for about 7 miles and
When I got home, I smelled a burned like smell and the engine light came on. It is as if the car is running with only three cylinders or so. The oil still looks very clean and it is at Level. It could be a coincidence and some thing else unrelated to oil change is happening? Could you help? The oil I used is called Super Tech SAE 10W-30 motor oil.


Answer
Hi Josee,
I doubt that the motor oil change has caused the problem unless there is something that got disturbed when the oil was changed, so look around any fittings that you needed to deal with in changing the oil.
If the check engine light is on then that means that the engine controller has detected a fault in the engine's running that would effect the pollution control systems. You should be able to get a free readout of the memory in the controller for a fault code number at an Autozone store. I would do that readout first, get the code number, what it means, what they say might be the fix, and how much. I don't have any experience or manuals for the Mazda engine but if the code numbers begin with P and are followed by 4-digit numbers then those are "universal". So let me know if that is the case and I might have an idea as to what to do.
Roland