Engine light on code P0300

[Jmalcolm]

I've been driving my Mazda protege 5 for 2 days now and it ran great but now all of a sudden it started acting up.. Engine light is on code P0300 random miss fire it's hard to start, lack of power and loss of power the the engine idle roughly, now the guy at part source seems to think it's the egr valve but I've looked on google and haven't seen anything about the egr valve being the problem now I've changed the plugs and the wires and that hasn't fixed anything but I have yet to replace the coils if I do that will it fix my problem

 

[esnave09]

It will more than likely fi the problem. Coils on these cars are known for suddenly quitting.

 

[Jmalcolm]

I got one new coil and switched it between the cylinders and it never fixed my problem I also replaced my intake hose because it had a hole in it and was throwing off my MAF sensor but I still haven't fixed my problem

 

[tweety2300]

90% of the time when one coil pack goes the other goes with it

You could try cleaning egr valve but that makes the idle jump and won't cause drivability issues.

Those are also all symptoms of a blown head gasket

 

[Maroon]

With it running, disconnect each fuel injector wire individually. If it is only one cylinder that is giving you problems, then that one will not make a difference when you unplug it while the rest will make a difference. This will at least narrow down your search.

The EGR doesn't cause misfire.

 

[Jmalcolm]

I'll have to look into the fuel injectors and see it I have a problem there but now I'm thinking it could be a fuel problem.. I just bought the car and working to get it safetied and the car has been sitting get for some time so I'm gunna try changing the fuel filter and see if that helps, where is the fuel filter located on the car??

 

[Maroon]

It is in the tank. Pull out the rear seat cushion and then remove the black cover. Under that you will find 8 or so rusted to s*** phillips screws that you stand no chance of removing without an angle grinder and some casualties. Just put the cover and the seat cushion back on and go try something else. Just kidding, maybe you'll get lucky and they won't be so rusty. You could rent the fuel pressure test tool from Autozone.

 

[hornsfan10609]

The EGR can cause a misfire but start with new spark plugs and wires if you already have two new coil packs.

 

[Jmalcolm]

It is in the tank. Pull out the rear seat cushion and then remove the black cover. Under that you will find 8 or so rusted to s*** phillips screws that you stand no chance of removing without an angle grinder and some casualties. Just put the cover and the seat cushion back on and go try something else. Just kidding, maybe you'll get lucky and they won't be so rusty. You could rent the fuel pressure test tool from Autozone.

Yeah your absolutely right there's no way I'm gunna be able to grt that sending unit off to change the fuel filter those screws are rusted right out I'm gunna have to try something else because the car drives fine other then the lack of power and acceleration and the rough idling

 

[Maroon]

Did you pull the injector wires yet?

 

[tweety2300]

It is in the tank. Pull out the rear seat cushion and then remove the black cover. Under that you will find 8 or so rusted to s*** phillips screws that you stand no chance of removing without an angle grinder and some casualties. Just put the cover and the seat cushion back on and go try something else. Just kidding, maybe you'll get lucky and they won't be so rusty. You could rent the fuel pressure test tool from Autozone.

Protege does not have a fuel filter. It has a sock on the end of the pump. Also look into an impact screw driver. Got the rusted dirt cakes ones off my 323 with years of rally with no issues. Couple taps and it's loose

 

[pcb]

Protege does not have a fuel filter.

Does So !!!

http://www.mazdas247.com/forum/show...ge-Your-Fuel-Filter-(lots-of-pics)&highlight=

 

[tweety2300]

Touch is just rather replace the whole pump at that point

 

[hornsfan10609]

It's the ignition system

 

[Maroon]

Okay....what about the ignition system?

 

[kms1990]

have you looked at the spark plugs for fouling? look for oil or tip fouling, how many miles are on it? random misfires when set alone are usually a system that feeds all cylinders so it could be fuel or air related. check your air intake boot (especially around the ribs) for rips that can cause misfiring. check for air leaks in the vacuum line as well. fuel pressure is another concern, rent that tester mentioned above and test your pump. check for leaking gaskets around the engine and check your pcv valve. next would be egr but this would usually throw a separate code. check your ignition wires as well.

 

[tweety2300]

Plugs or wires generally set of 301,302,303 or 304 indicating the exact cylinder. 300 means it's coming from different cylinders and a rich or lean condition causing a misfire should also set off one for the o2 sensor as well

 

[choinumni4]

I've been driving my Mazda protege 5 for 2 days now and it ran great but now all of a sudden it started acting up.. Engine light is on code P0300 random miss fire it's hard to start, lack of power and loss of power the the engine idle roughly, now the guy at part source seems to think it's the egr valve but I've looked on google and haven't seen anything about the egr valve being the problem now I've changed the plugs and the wires and that hasn't fixed anything but I have yet to replace the coils if I do that will it fix my problem

Hi here is what I have dealt with since owning this car from 2005 to now.
- Rough idle and random stumbling at low speeds. Fixed this with replacing the air intake hose which was cracked. $35 online purchase, 2007.
- Rough idle with a p300 cel light. Changed the coil packs and fixed the problem. $80 OReileys 2010.

- Rough idle with a p301 cel light that was flashing off and on. Fixed it with new plug wires after diagnosing each one with a multimeter and found the # 1 wire had a reading of 7k ohms resistance and the other wire was at 3k ohms so this took care of the problem with a new set of wires. $ 30 at OReileys. I also replaced the spark plugs and air filter while I was at it since I have been neglecting the tune ups.
- I have ran a bottle of Seafoam through it to keep the egr clean but have never had to take this off yet. Which looks like a @$) to get to the 2 bolts it on anyways.

Good luck and hope you find the problem to be a simple and cheap one.

 

[Jmalcolm]

Update!
Since I have been busy and haven't had much time to reply to all the helpful responses after replacing my cracked intake hose and changing all the spark plugs and coil packs and almost attempting to look at my fuel filter/sending unit to see of it was a fuel issue I thought I'd take a look at my egr valve turns out that was the problem all along it was seized right up! After a good cleaning and Reassembly everything is good again!

 

[pcb]

Keep the "Canadian" EGR in mind then you won't have to deal with this every 6 months.
Its got coolant lines and a vent line attached to it so it never causes a problem.