I've developed a missfire under load and varified via the Aeroforce Scan Gauge. I replaced every plug and noticed #4 plug had a slight crack in the porcelain. After the plug change everything seemed well untill a couple days later and again the Aeroforce confirmed the miss. Can the Aeroforce help indentify which cylinder is causing the missfire?

The P030X code will tell you, the number of the X is the cylinder. The p0300 is random misfire and not on any one cylinder. Check that plug in the same cylinder. If you see what looks like a crack it may be a carbon trace. If that'* the case, replace your plug wires as well as that plug.

Some Aeroforces do have the ability to show you the 6 cylinders and which ones are misfiring. This depends on the version of the gauge.

You can find this feature by pressing both buttons at the same time and looking for "misfires" in the listing of Scan/Play/DTC'*. etc etc.

If your gauge does not have the feature, it can be sent into Aeroforce for an update. There'* a fee associated, not sure how much that costs these days.

DANTHURS:

Dan, I don't believe I get a code with the Aeroforce, only the number of missfires, that'* how I verified it is truly a missfire. As for the plug, it was definately a crack since I ran my nail across it and felt it. Usually a carbon trace isn't as deep and has a different feeling. I believe you posted "how to check plug wires". I'll have to see if I can locate that tech info.

BillBoost37:

I've pressed both buttons before and nothing happened, do I need to hold it down for X amount of seconds and wait. At the moment it just states I have around 31 missfires but that depends on how long I run it under load....obviously.

Thanks for the reply guys.

Frank...no worries. It'* being a finicky if it'* nto popping up the menu. I've texted a local guy by the name of Mick. This guy is an ace with things like this and should be able to help you out in record time.

Please clear an area in the driveway/garage and he'll be home in record time to help out.

New info has been obtained. Told you that Mick guy was quick.

The coil, ICM, plug, wires etc have all been changed a couple times, and the issue always comes back to #4.

At this point, I'd suggest looking over the routing of the wire to ensure it'* not arching or having other issues. Considering how the plug is being changed, meaning from driverside etc and how much torque etc. Consider changing it from a different angle or with a different socket. And....while you are at it.. compression test.

The wire does not come in contact with the 02 sensor and I removed the strut bar when changing the plug, as well made sure I didn't overtighten and crack the new plug. The problem went away as soon as the new plugs were installed and came back couple days later.

Mick is presently at work, so that is a priority, next would be modding his car. .

That doesn't mean he won't help if I ask him nicely. You know how I can be that way. Plus..he'* loves me. (I know cause he said it about 100 times one night during Beer Pong).

Almost sounds like that plug is fouling out over a couple of weeks. Any oil or build up on it that you want to tell us about?

How does the post look on the plug? You've removed the spark as a problem. That leaves fuel, or mechanical. Try swapping injectors and see if the problem follows. If not, then a compression test. Keep in mind, a compression test may not show if you have a broken valve spring. Seen that twice now. Everything tests good but misfire is still there. Remove the valve cover and there it is, a broken valve spring.

how do you change a fuel injector?