P0300 Lean Misfire?
#1
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P0300 Lean Misfire?
So my last post I mentioned I had a misfire that would make my car bog down above 6500+ RPMS. I replaced the plugs, and since then the car doesn't bog anymore. However, I still have a P0300 lean misfire. This doesn't really happen around town or general driving, it usually happens above 60mph or so. But it doesn't affect the car in any way. The thing im noticing is the CEL blinking will stay on when I floor it above 70 or so. I've been up to 140, it made it there no problem, no bogging, no hesitation, just constant CEL flashing. Like I said, it doesn't do it driving around the city. Another thing I noticed is sometimes, around 4-5k if I give it a little gas and let go it will backfire. Even a slight tap on the gas. Sometimes it hesitates a bit. But usually then it'll just go.
So far, what I've done to fix the misfire is:
New plugs installed maybe 200 miles ago
New 10mm racing wires
Aftermarket coils
Cleaned the EGR valve
Seafoamed the car a month ago
Cleaned MAF sensor
Cleaned the whole intake
Took out the Agency Power Midpipe & made sure nothing was blocking it (it was clear)
So ive done most of the basic stuff
Fuel pump checked, ran fine
There's only 3 things I think it is:
My pod filter has been getting wet recently with all the rain (its the AEM one so its behind the front bumper) and its pretty dirty as well.
Possibly fuel injectors.
Maybe bad compression (nearest Mazda dealer is a good ways away so can't get one done at the moment)
Also, the idle is pretty bad. It surges a bit. Sometimes it will sit on idle pretty good when its warm, sometimes it dips to around 500 then surges back up. But it surges for the most part the whole time. Starting seems to be fine.
Any ideas? Any help will be appreciated .
So far, what I've done to fix the misfire is:
New plugs installed maybe 200 miles ago
New 10mm racing wires
Aftermarket coils
Cleaned the EGR valve
Seafoamed the car a month ago
Cleaned MAF sensor
Cleaned the whole intake
Took out the Agency Power Midpipe & made sure nothing was blocking it (it was clear)
So ive done most of the basic stuff
Fuel pump checked, ran fine
There's only 3 things I think it is:
My pod filter has been getting wet recently with all the rain (its the AEM one so its behind the front bumper) and its pretty dirty as well.
Possibly fuel injectors.
Maybe bad compression (nearest Mazda dealer is a good ways away so can't get one done at the moment)
Also, the idle is pretty bad. It surges a bit. Sometimes it will sit on idle pretty good when its warm, sometimes it dips to around 500 then surges back up. But it surges for the most part the whole time. Starting seems to be fine.
Any ideas? Any help will be appreciated .
#2
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P0300 Lean Misfire?
There's only 3 things I think it is:
My pod filter has been getting wet recently with all the rain (its the AEM one so its behind the front bumper) and its pretty dirty as well.
Possibly fuel injectors.
Maybe bad compression (nearest Mazda dealer is a good ways away so can't get one done at the moment)
Also, the idle is pretty bad.
My pod filter has been getting wet recently with all the rain (its the AEM one so its behind the front bumper) and its pretty dirty as well.
Possibly fuel injectors.
Maybe bad compression (nearest Mazda dealer is a good ways away so can't get one done at the moment)
Also, the idle is pretty bad.
Did you double check to make sure they're in the right order, and they're all delivering spark?
How dirty is the air filter? Clean it. And keep it clean.
What makes you think fuel injectors? And what are you thinking the issue is?
#3
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What type of wires and coils did you replace the existing ones with? Aftermarket doesn't always mean "better".
Did you double check to make sure they're in the right order, and they're all delivering spark?
How dirty is the air filter? Clean it. And keep it clean.
What makes you think fuel injectors? And what are you thinking the issue is?
Did you double check to make sure they're in the right order, and they're all delivering spark?
How dirty is the air filter? Clean it. And keep it clean.
What makes you think fuel injectors? And what are you thinking the issue is?
I've quadruple checked all the plugs and wires to make sure they're in the right order. And all the plugs are sparking.
The air filter isn't terrible, I just cleaned it a month ago but it could definitely be replaced. I'm gonna do that next paycheck. And I'm thinking fuel injectors because all the symptoms of bad injectors have been sounding like what's wrong. I'm going to get them tested to be sure. What's your best guess?
#5
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#7
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I did. But I took a little testing today. Replaced the pod filter with a new one, same problem. But upon testing, I slowly revved it up while in neutral and not moving. And it always happens at around the 6250-6500 mark and up. But it always does it when my revs hit 6500 while revving. CEL flashed, etc. Then when I'm driving it also is fine til 6500 then slight hesitation then it goes. Any idea as to what happens at that RPM?
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