P0302 Engine Misfire, with a twist!
 

Okay, im gonna start off first by stating ive been a member for over a year, and that prior to this post I have done all the research/testing I am capable of doing myself, and with the tools I have.

My car is a 2009 sport which ive had for one year. I am the second owner, with 62XXX miles on her 41XXX when I bought it in 2012, factory engine. Current mods include, b&b midpipe, custom dual exhaust, and just a cone filter. I have a stage 1 competition clutch, with a competition clutch lightweight flywheel. No other engine/exhaust mods, and car was stock when I bought it and very, very, very clean. Engine oil is always on schedule, and im always checking fluid. Although I am pretty aggressive with the car, constant redlines are the worst that I do. I don't do burnouts, or clutch dumps, nor do I try and drift...anymore.

THE STORY: About 2 weeks ago I took my 8 out for a nightly cruise here in VA with a friend of mine. I drove probably 25 miles all together. Well everything seemed fine, no hesitation, no stalling, no vibrations, nothing. Just like normal. The next day I go to take my car out and its acting weird. Long story short car goes into limp mode, and I have to limp back home (being respectful that its in danger). Get home, check it out, look at a couple minor things, see no issues. Next day car starts fine, only issue is its misfiring, but only above 5XXX rpms. Anything under and the car is perfectly fine. Check engine light blinks 3 times if I go over 5XXX rpms. So I get it checked out at the auto store, get some new plugs after taking mine out and seeing that the old ones were no good. No black burn marks, no chips or cracks. Just brown on the end with the spark. Install new plugs, wires/coils looked fine. Took the car out after topping off oil, and fluids, and letting it warm up. Same issue, still misfiring over 5XXX rpms. Next decision is to replace coils, so I order up some coils from advance auto. Coils I received from them are BWD E1001 coils. Got home, installed and noticed oil in the intake/throttle body. Oil had been previously changed 4 days prior. Cleaned it all up, cleaned the MAF and throttle body, installed coils, 3 old coils had white burn marks on the bottom. So, after coil installation, I drive down the road, same issue! still missing over 5XXX rpms. Next order of business is I decide to order wires. Call autozone and ordered some duralast wires. So, when I put the wires on I decided to switch the rear plugs to the front, and front to rear. I also switched the coils in effort to see if any component was bad. I also removed/cleaned/tested the ESS, removed/cleaned the MAF. Hopped in the car and its still missing. So, what I did now was went to the auto store and got some seafoam, put half in the oil and half in the gas. Also put 9 gallons of new gas, along with my first time premixing :) that seemed to help out, car idles smoother, no hesitation while taking off/under load, but im still missing over 5XXX rpms, but not as bad. Before all of this the car sounded like a sick lion, almost like a cammed piston engine, now its like a pur after 6XXX rpms. I haven't ran it past 5XXX rpms until this morning, and the power is there, no issues just misfiring. There is some smoke if I wind it up to redline, and if I stay WOT the car will "bog" and spit out a huge plum of smoke. Needless to say I wont try that again. So to recap:

What has been done:
New plugs NGK oem replacements
New Duralast OEM wires
New Coils OEM replacement
Cleaned ESS
Cleaned MAF
Cleaned intake/throttle body
New oil change
Premix
Seafoam in oil and gas
Ecu has been reset as well as ESS
"ROOM" fuse pulled inside cabin fuse box

What has not been done:
Compression test
Upgraded/stronger coils and wires
Oil injectors tests
Fuel injectors tests
ESS test
SSV cleaning
Seafoam into vacuum lines to clear out carbon

I tested the coils via multimeter, and they read in close to the OEM coils I had one, although I need to retest for the numbers because I didn't write them down (stupid I know). I followed RIWWP's write up as well as countless others in effort to find a solution. There is blue smoke coming from the exhaust after idling for 5/10 minutes. Another test that I did was pulled the wire off the coil to see the sparks, and it is showing a bright red/pink spark. I have not tested the plugs for firing. Ive spent hours searching and reading and trial and error, and I just thought maybe someone has some insight on what may be wrong or an issue.


Im planning on upgrading to the LS2 coils and wires in hopes that helps the issue with a weak spark/ignition. I don't know the resistances to any of the coils/ESS/oil/fuel injectors to be able to test them. I know how to test, just unsure of the numbers to use as a guideline. Again, any help is greatly appreciated.

Before you keep throwing money at continuing to replace coils, work through the misfire thread in my sig.

Clean the ESS, reset the profile, and I bet your problem will be gone. If not, you may be spitting oil into the intake at higher RPM, leading to misfires. Your healthy ignition is clearly not causing the problem, so continuing to try to upgrade isn't going to get you anywhere in relation to this problem itself.

Thanks RIWWP, ive read through it about 10 tens by now :/ ive done everything I can. Still no luck. Ive cleaned it, reset it and its still misfiring. I was thinking maybe the replacements I put in aren't strong enough??

Unless you bought the wrong items, the problem isn't your ignition.

BTW: The OEM ignition test is worthless. If you want a better test, get an ignition tester, looks like a spark plug with a clamp Should be a clear blue spark that is consistent in intensity, color, frequency, and shape.

Cat, O2 sensor, oil in the intake, and compression are the points I'd go to next.

That's what I was thinking. Ill pick up an ignition tester hopefully today when I get off. I have no cat, just a midpipe, O2 sensor hasn't thrown any codes yet but ill inspect it anways. The oil I believe comes from the blowback when I tried to go above 5XXX rpms and it bogged down and went to limp mode. Compression will be tested soon. I know that my exhaust does have a hole in one of the mufflers (pothole scrape) and I think the joint where the header connects to the midpipe has a leak. Its audible from outside the car. Would that be possible to cause a misfire with the exhaust like that?

Can we delete this thread so I may move it to series 2 tech and troubleshooting? Thanks

Moved. Just as easy as deleting, and if I deleted it, you would lose the post credit here and then be unable to make a thread there :)

Thank you sir! I don't believe I have those functions available to me. I appreciate it.

Okay, after a couple hours more of research and reading I feel like im going to do a lot of work this weekend. Heres what I have planned:

1. Remove all intake items (from filter to UIM)
2. Clean what is necessary or dirty
3. Remove ESS/ESPS and clean again
4. Remove spark plugs, wires, and coils
5. Remove 02 sensors and clean
6. Remove SSV and clean
7. Check all other air valves that I can
8. Re-install all cleaned/removed parts
9. Re-install factory air box/filter and VFAD
10. Test spark plugs/wires/coils for spark via Spark Tester
11. Seafoam/Mazda Cleaner into intake and vacuum ports
12. Take exhaust to get welded up and factory muffler re-installed (keeping midpipe though)
13. Oil change with needed fluids topped off

Keeping fingers crossed that this solves some or all of my problems

Just curious how do you plan on cleaning the O2 sensors? I have 135, 000+ on my 04 with the original upstream sensor.. replaced the rear one about 8 months ago due to CEL...

I just use electronic cleaner. Spray it on and let is soak.


Here's a video showing misfires. It'll happen under 5k rpms, but only at WOT and under load.

Huh.

That isn't something I've seen before. Typically misfires have RPM as a component of the conditions under which it happens, but not so strictly predictable where it RPM is the only thing that matters.

I admit you have me stumped.

Curious, is the misfire code the only one behind that CEL light when it's steady?

Doesn't part of the intake piping change somewhere around the 5,000 rpm range?

SSV opens at 3,750
VFAD opens at 5,500
APV opens at 6,250
VIV opens at 7,250

All of these are the base RPM points, apparently there is a load component of tthat can adjust this up or down some.

If this was caused by a sudden change of air flow like that, it should stop misfiring after a very short moment as the engine would stabilize to the adjustment.

I almost want to suggest that maybe the ECU only thinks it's seeing a misfire, when it isn't, though I don't know enough about the detection method to know if this might have any weight.

You aren't the only one stumped! This has been going on for almost a month. This morning it seemed to drive somewhat better this morning. Oil light was blinking as well :/ guess I have to find why it has used that much oil.

That may be a clue. The oil light is steady if it's low, it only blinks if there is an OMP fault.

You might have an electrical issue lurking under there.

yea came on at engine start, blinked for maybe 5/10 seconds with beeps then stopped. First time its done it since the oil change. Has done it before when oil was low (checked dipstick)

to me it sounds like bad omp (s?) and the car trying to save itself...

Not really. If the ECU detects OMP failure, it can certainly enter a limp mode, but that limp mode will not include misfiring. The ECU will only classify something as misfiring if it's expecting the engine to fire, and it doesn't. If the ECU is cutting fuel and spark cycles intentionally, it will know that it's doing it, and won't be then recording that as a misfire.

So to me, something electrical related is causing both problems, possibly vacuum related, but less likely.

For it to be dead on at 5K, electrical makes sense, but nothing is changing at that RPM, does it happen under all load conditions at 5K or only at 5K under WOT.

An OMP would not cause this, oil in the inlet pipe could be causing the problem like the OP mentioned if for some reason at 5K, the crank is becoming unevenly pressurized and spitting oil into the crank.

I would through a cheap catch can on it and see, if that is the case then you are probably losing compression at 5K too, and would get it checked.

Just my thoughts, Im more than likely wrong. But just in case.

from this^^ it seems IMO that the omp's are affected, could be bad omp's or something electrical affecting them as well...

The video shows it triggering at exactly 5,000rpm even if he takes 10 seconds to get there from 4,900rpm. Hmm, well, that's indicated RPM, I wonder what the actual RPM is underneath?

Getting the OBD2 rpm it's triggering at may be beneficial.

I agree that the OMP isn't causing the misfire, I think something else is causing both the OMP fault and the misfire.

Yeah, didn't watch the video :uhh:

Oil light typically comes on when im low. ill check it when I leave work tonight to see where it stands cold. Under acceleration the light will blink or trigger at 5k rpms and above and at WOT it will instantly misfire within seconds, that's any gear, and speed, once it goes past 5k rpms. I have a catch can ordered but wont be here till after the weekend.


Not sure exactly what to look for electrically for the OMPs. Its my understanding they are in the engine? or at least involve a lot of moving and removal of engine accessories or parts.

In the upper rpm range is when it gets worse. Misfires are audible and the engine sounds like its "growling" or "purring." If I stay on the accelerator or WOT itll bog and slow down, followed by a trail of blue smoke (burning oil)

Still coming with crank case oil, keep in mind the dipstick is about a quart, if even a little of that enters the intake it will cause problems and might not be noticeable and could be misinterpreted as normal OMP volume.