I had the same problem on my 98 Mazda 626 and the O2 sensor was faulty.....
where is the location of all o2 sensars in 99 Mazda 626
rggerger
The cooling fan relay on a 1998 Mazda 626 is located in the engine compartment near the firewall. It is housed in a protective box with latches.
Does your cooling fan work?
on the throttle body
Yes, it has a speed sensor, about $125 online.
On the 2000 626 it is directly under the air filter box.
probably the fan relay
Mazda 626 frm 1996 doesn't have O2 sensors, have you ECU/PCM inspected, it might have a minor damage.
the ABS sensor is bad.
It's part of the distributor