p0300 is random missfire. i would first start by changing/checking the spark plugs. on a 2.5, check the ignition wires, then the dist cap. the distributor itself is a common problem. on a 2.3, it is a cop system, if 2 or more coils are bad, it will throw the 0300. but start with fresh plugs.
P0300 Diagnostic Code - Random Misfire
Symptoms.
Engine may stumble or miss
Engine may be hard to start
you may notice no issues
Cause
Failing spark plugs or spark plug wires
Bad coil or coil pack
Failing oxygen sensor(s)
Bad fuel injector or more than one
Stuck exhaust valve
Bad catalytic converter
EGR valve or valve passage clogging
Bad camshaft position sensor
Bad PCM or ECM
The Fix
Best first action is a tune up, new plugs, wires, inspect all hoses and wire connections then reset the code. If it returns you will need to narrow it down to a system, coils and coil packs should be tested, catalytic converters for function ( do you smell rotten eggs?). A misfire that jumps cylinders could indicate a lean condition, do you have any other codes along with the 300? this will help clue you in to the source, check valve function to make sure they are opening and closing fully.
This is probably pone of the most difficult codes to troubleshoot, so start with the basics and work your way into the more expensive options, in many cases a good old tune up solves the problem, back it up with a fuel system cleaning and see where you stand.
Mazda Discontinued the Millenia in 2002.
Mazda Millenia hoods from models 1995 to 2002 will fit on a 1995 Mazda Millenia. The Mazda Millenia was first launched in 1995.
Were you able to fix this? I have 5 codes on my 2000 Mazda millenia and 4 of them are same as above :-)The codes I have are:- P0173P0431 P0105P1173P0170 The last repair shop i went told me that it could be a vacuum leak... I am yet to fix these......
timing marks on 2002 Mazda millennium 2.5 dohc
1.1mm(.044in)
Millenia is the terrm used for more than one millenium, which consists of a thousand years. Millenia is also the name of Mazda's flagship luxury sedan from 1995 to 2002. !!! MILLENIA in the case of the Mazda means you must spent 1000 bucks a year on her in Maintanance to keep her on the road.
The EGR valve is connected above the water hose on the 2002 Mazda Millennia. The EGR valve is responsible for lowering the temperature of the fuel.
take the back seat out and it's there at the trunk space
I have a 2002 Millenia-S and removing and reattaching the + battery cable does reset the check engine light.Answertry unhooking the positive cable to the battery...this works on my 97 millenia
passenger side front by windshied washer reservoir
Locking Mechanism controlled by your brake pedal has failed. It will need to be repaired
Fix the problem it is telling you about - It will jsut come back on if you dont M