Trouble code P0421 means: Catalyst Efficiency Below Normal (Bank 1)
With 2.5 engine it will be on the rear lower of back head. It is an electronic EGR valve with a 6pin plug going to it.
how to reset check engine light on 1992 Mazda mpv
The check engine light on a Mazda Tribute gives warning of potential problems. It can signal overheating, low oil, or engine misfires.
I'm not sure but you may need to check the engine.
If the check engine light is blinking , an engine cylinder misfire has been detected
A flashing check engine light means an engine cylinder misfire has been detected
A check engine code 332 for a 1994 Mazda 626 means that the EGR valve's voltage is lower than it is expected to be. The ERG valve is part of your Mazda's emission control system.
ODO
If your check engine light is flashing an engine cylinder misfire has been detected
When the check engine light comes on, it's a good indication that something is wrong with your engine.
There are numerous warning lights for a Mazda RX8. Some of the warning lights are for engine oil, charging system, ABS, and check engine.
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