Recent content by Hornet99

SOLVED: That 54ohm value was bothering me, so instead of bypassing the ground near HPFP to battery negative, I bypassed the ignition coil connector ground by back probing that wire directly to the ground near the HPFP. I did this on two ignition coils at the same time and the car started. Not...

Car: 2012 Mazdaspeed 3 2.3L Issue: No recent changes or accidents, car worked fine one day and next day would not start. Installed new battery and no change - 13.8v measured. For diagnostic tools I have a Cobb AccessPort, OBD II with Forscan, test light, multi-meter and backprobes. No...

Problem was resolved with 4 new NGK plugs, purchased at Autozone. Bucking/stumbling is gone. Thanks again! -Dave

Thanks all for the quick responses! I will return these plugs and buy from a reputable source, plus follow advice regarding no low RPM to WOT Do you think the blown plug was the likely root cause and not just a symptom of a bigger issue? What should I do about the existing carbon build-up...

First a little background: I'm the second owner (bought Aug '22 with 155k miles) of 2012 MS3 with Cobb Stage 2, tuned, HPFP. Turbo blew within first month and was replaced by a mechanic I trust. Since I've owned it the car has been driven very gently - just used on short (10-20 mile) trips as...