Thread: blinking Check Engine Light

You are right, theres nothing bad about that. Its just that all my other wires/plugs are LIKE NEW. When I decide to get a tune-up i will then do all plugs/wires and other stuff while im at it. Im sure theres nothing bad going to happen. Thanks for your help and concern though.

Changing spark plugs one at a time to cure cylinder misfire condition is the beginning of a never ending saga that no one should EVER have to endure, but still, we do. I am going to try to save someone that grief, even if I can only help one soul.

Here is MY story.

I bought the 2000 GTP in Jan., 2008. No problem with engine light until Feb., 2010.

First time engine code P0303 (Cyl.3 misfire, AutoZone).

Cable terminal on the #3 Ignition pack was corroded. I did the minimum. I cleaned the Cable terminal. Engine light cleared. One week later,

Second time engine code P0303 (Cyl.3 misfire, AutoZone).

Cable terminal on the #3 Ignition pack was, still clean. Plug number #3 melted (and I DO MEAN Melted!) I failed to look at it the first time. Second time, I still did the minimum. I replaced the #3 plug (with a copper plug as ID by AutoZone) and #3 wire. Engine light cleared. Another week passed (can anyone finish this story before I can?).

Third time engine code P0301 (Cyl.1 misfire, AutoZone).

I did what everyone said I should have the first time (almost...).
I changed all the plugs and wires. (Except the one that was blocked by the front O2 sensor (stock exhaust setup, few here may still have). Engine light cleared. Not replacing all plugs the first time, big mistake. I failed to correctly ID the melted plug as "iridium", it was (AND SO WERE THE REMAINING PLUGS). So, I ran 1 new copper and 5 old "iridium" for about two weeks. Then, I made my second huge mistake. I ALMOST replaced ALL my plugs and wires with new copper, leaving the #6 "iridium" because it was the PITA plug behind the O2 sensor, I was quite sure nothing seriously wrong could come of it. I was right, I thought, until 1 month later.

Fourth time engine code P0306 (Cyl.6 misfire, AutoZone).
(This time it also flashes some time).

I think I am going to follow the advice of the guys here and replace ALL the plugs and ALL the wires TOMORROW!

I have already acquired the FREE loaner tool (for the PITA #6 plug).

I have decided on plugs from NGK, IRIDIUM IX, TR55IX, 7164 on a stock setup, for their longevity. No other mods, (quite yet). I have already acquired these.

I have decided on wires from ACCEL, 8MM Super Stock Spiral Wire, HI TEMP, BLUE Jacket, 5040B. I have already acquired these, also.

I have prepped my fuel system using SeaFoam for GAS engines.

And best of all I know I will not regret the “initial” expense because this has already been a PITA, to me. I sincerely hope this helps at least one person out there. I will try to update with details as they become available.

whats the weather like ....obviously dry pavement when ur "puting the peddel down"? was guna say misfire caused from wet coil packs? grounding out? but reiterating...plugs, wires, cat

Originally Posted by supercharged06

whats the weather like ....obviously dry pavement when ur "puting the peddel down"? was guna say misfire caused from wet coil packs? grounding out? but reiterating...plugs, wires, cat

Supercharged06,

I just came in for a quick glance at the coil pack diagram and a beverage, when I saw your post.

YES! Weather has been rainy, very rainy!
Yep, this is Houston; August is the beginning of the hurricane season.
We have been getting POUNDED with rain.
Do you think the wheel wells might be allowing water in?

FYI:
Have you seen this happen?
I did find a hairline porcelain crack in the #6 plug.
I only have 2, 4 and 6 plugs out.
Could all this be the symptom or extension of the wet coil packs, grounding out?

I'll check it out after looking into the CAT problem.

Originally Posted by rmcardle3

I'll check it out after looking into the CAT problem.

Ok, great results.
8mm plug wires, done.
Iridium plugs gapped 53-55, done.
Missfire condition, gone.
Seafoam did cause a "latent" engine code 420.
Delayed code HO2S 2 heated oxygen sensor, catalyst efficientcy~36 hours later.
Disconnected the battery, overnight.
HO2S 2 condition, gone (now going on 48 hours).

Great advice/information from this site! Thanks!

Whoa, gappping iridium plugs?

And why not just run them at 0.060?

thats just it.... they WERE adjusted for the vehicle you were going to put them in.

The second 5 means the plugs are gapped to 0.059 from the factory.

Did I mention I cleared all my missfire codes? So, your saying the .053-.055 (instead of the .060) spark gap, on a supercharged 3800 is the last thing that should be modified, after the pully down swap and after all other mods?

FYI: I took this thread out of context:
http://www.grandprixforums.net/plug-gapping-21896.html

(I thought gap mods where the old school, easiest mods for higher compression [superchargers] and the higher rpms.) Da*&, it has been running at the top of it's game for the past week.
(all stock, except for the cone filter intake).

Whatever, Ok so you guys are saying I need to widen my gaps back to .060 because other wise missfire might come back, if that sounds right? Ok. Thanks guys.

No actually, wider gap = more possibility for missing.

Leave it, for now? Ok.

Yea, compared to the way it ran (accelerated) before "with the misfire", I can use more of the accelerater pedal now. Ok, thanks guys.