A few weeks ago I mentioned that while returning from a long trip and on the last 400-500 miles I had an intermittent miss that developed while getting off the interstate to get fuel. After refueling, it still had the miss but it was a Saturday night about 11:00 and just north of Knoxville with virtually no choice but see if it would smooth out once upon the interstate again. Long story short: it did smooth out after maybe 10-20 miles and all was good the rest of the trip. Weird, I thought, but hey the ol' gal had over 150K miles at the time and was pretty certain the coils had never been changed so...

I started out on a SEARCH of the forum to see if I could nail down the exact problem. I came across THIS THREAD and a couple others but I thought Arthor Dalton did a great service for the forum (and Jim Villers) helping us understand what to look for with these missing issues so I kinda followed that particular thread over the other threads I ran across.

I decided to order just two new BOSCH coils from Pelican and not the under-the-coil connectors since I knew that I had changed those along with new BOSCH F8DC4 plugs back a couple years ago (a realtime check of my spreadsheet records told a slightly different story!). In reality, I have 37K on the plugs and one of the connectors while ~25K on the other two connectors. Earlier this week I ran a code check to see what might pop up and this is what I found:

Factory Diagnostic LED -

• 2 "Heated oxygen sensor faulty"
• 4 "Air injection system faulty hot film mass air flow sensor with hot wire"
• 5 "Exhaust gas recirculation faulty"
• 6 " Idle speed control faulty"
• 7 "Ignition system faulty"
• 26 "Upshift delay faulty"

PIN #8 -

• 9 "O2S (before TWC) - voltage too high, circuit open or voltage implausible"
• 21 "Ignition output 3 or ignition coil for cylinder 1 and 6"

PIN14 -

• 6 "Starter lockout/backup lamp switch"
• 14 "Closed throttle position contact switch"

Given the code #21 and #7 I thought I'd simply go ahead and try replacing the cyl 6 coil and see if that fixes it. I also thought that since the car had the original 'blue labled' coils, it was time to start replacing them. I installed the one coil last evening, started it, sure seemed to run smoother, then took it out for a spin. Wow! It seemed to be 'HEALED'! Pulled back into the garage for the evening and shut off the lights. Got up this morning to go on a ~50 mile one way trip and not 3 miles from home it started running really rough! Considerably rougher than the previous encounters. Returned immediately to the garage, took another car on the trip and now I'm home trying to figure this out!

Ran another code check: (Cleared after previous check)

Factory Diagnostics LED -

• 6 "Idle speed control faulty"
• 7 "Ignition system faulty"
• 26 "Upshift delay faulty"

PIN #8 -

• 9 "O2S (before TWC) - voltage too high, circuit open or voltage implausible"
• 21 "Ignition output 3 or ignition coil for cylinder 1 and 6"

PIN #14 -

• 6 "Starter lockout/backup lamp switch"

Where should I be going from here? Your help will be greatly appreciated

__________________
Dale