P0300 CEL is driving me crazy

[desertmike680]

So after re gapping my spark plugs to .025 and reseting my car, the CEL comes back a day later. I have read all the posts about this issue and am well aware of it. I called Mazda in regards to it and they stated that their not even sure what the plugs should be gapped at. Imagine that...

My mods include a Fujita cold air, COBB turbo inlet and a Turbosmart dualport, in which I just oiled up last week and I keep the spring pretty loose.

Any other suggestions to what we can do to prevent our MS6 from misfiring?

Thanks

Mike

 

[decoy]

if im not misstaken, p0300 is random missfire. a couple of things would make this code. #1 one or more coils are bad. pull one at a time to see if idle changes. #2 from what i have seen is that the cat. converter could be clogged. simply removing down pipe and shine through it with a flash light looking small broken materials. since you have a turbo, this may not be much help. i dont mess with turbo engins alot.

on another thought, try unplugging the mass air flow sensor after you start the car to see if runs better. you might have a bad sensor and the car could be putting to much fuel in the cylinders

 

[Mistersix]

these are the stock plugs you regapped? maybe they got damaged when you regapped them? the solution may simply be new plugs.

 

[desertmike680]

Thanks for the input. I actually was throwing the CEL before regapping the plugs. I bought the plugs new in the spring, and just re gapped them last week. Their the same as stock though. NGK Iridiums. I called Mazda and made an apt for next Tuesday. Thanks again.

 

[decoy]

let us know what they find

 

[brianguild]

hey desertmike, I am in the same boat as you. P0300, but my car is bone stock. Code keeps coming back, dealership cant figure it out. Dealership has replaced low pressure fuel pump, plugs so far, but code still comes occasionally. I am scheduled to go into the dealership next week for a severe engine decarbon process. Have you had any luck fixing the problem? Did Mazda ever give you an worthwhile info?

 

[desertmike680]

Well I just got my car back from the Dealership on Wed in regards to CEL p0301. They replaced the coil pack and fouled spark plug from cylinder 1....but not even 24 hours later, the CEL came back. So I'll have to give them a call again today.

 

[brianguild]

Mike, there is a condition on this car where the ECT (coolant temp sensor) can fail without passing that specific code. My dealership sent a senior tech directly from Japan to diagnose my car because they couldn't find the problem. My ECT was replaced, and since, the P0300 hasn't (yet) returned after about 2000 miles. YMMV, but if your frustration level is increasing, and they haven't figured out the problem, it will be something to have them take a look at. My dealership said they had no way to detect this was the problem, due to the way the ECT failed and didn't pass the code.