I changed my spark plugs using the DIY on here with the ngk iridium ix plugs. Installed everything following the guide, then bolted everything back up, and started the car up. It was idling roughly and then the service engine light came on. I checked it over, everything is plugged in properly, I even reset the ecu to see if that would help. I am just wondering if anyone would know what would cause this short of pulling the code?

 

1. You plugged the electrical connectors into the coil packs in the incorrect order. Check FSM for correct bank 1 and bank 2 order from front to back.
2. The spark plugs are not gaped correctly. Check gap.
3. You left the vacuum line for the brake booster disconnected or put the hose on in reverse. The hose is directional.
4. One or more of the coil packs was damaged upon removal. FSM details troubleshooting. Use a metric ruler.
5. There is a vacuum leak. Re-torque upper and lower plenum. Check intake after the Mass Airflow Sensor.
6. Replace metal gaskets for upper and lower plenum if damaged.

 

I bet you #4 and #6 connectors are swapped

Those are the 2 cylinders closest to the firewall on the drivers side. They commonly get swapped on accident creating a random misfire code and can cause catastrophic damage if you leave it that way.

 

Thanks for the help guys. After taking it all apart again, apparantly the anti-seize had somehow made its way down from the top threads of the spark plugs down to the tips. I am unsure how this happened, but once removed, the car is back up and running. Now I just have to remove the bolt that snapped putting the #6 coil pack back on, as the easy out broke trying to remove it

 

weird. glad you found the problem though.

 

Yah, I was glad it was nothing major. Cant say I am to impressed with the antiseize though, I was miffed when I found out that was the cause. Now to fix that broken bolt, that is going to be a headache to remove, I can tell already. Any ideas on how to secure that sixth coilpack in the meantime as I feel weary driving it around with it not screwed in.

 

It should lock into place itself....the screw is just for backup/security. Consider putting something between the wireloom and the coilpack to keep downward pressure on it?

Just learn how to use easy-outs properly next time haha j/k

 

Thanks. Looks like it is holding itself into place fine, but I will try to find somethin to hold it down. Now I have to figure out how to replace that brass fitting aswell. I wasnt the one using the easy out, my friend was attempting to remove it

 

Kick your friend. Improper use of tools just creates more problems. With easy outs you have to make sure you drill a large enough hole for th bit.

 

and deep enough....learned that one the hardway on my mustang

 

Well I believe that is what happened as it spread, so the hole was obviously not large enough. Kind of annoying but oh well, it can be fixed. I was just glad to have found the problem with the CEL. Now I have some better bits to drill out both the end of the easyout that broke off and the rest of the screw. I tell ya, this car gives me nothing but headaches.

 

Use cobalt drill bit to remove remains of broken bolt/ez out. Good lesson, never use an ez out on small diameter bolts they usually break.

Center punch area before drilling to make it easier for alignment.

Brass fitting is is molded into valve cover, you most likely damage the valve cover boss trying to remove fitting.

 

Ya, I will try and remove it very carefully and fasten it, then if it is molded into the valve cover, I can look forward to getting a new valve cover in the spring.

 

This just happened recently to me (Coil connectors reversed for #4 and #6 after changing my spark plugs at the technical school. It took a little while to figure it out as the car was idling. The car was started up on 3 to 4 separate occasions and the engine ran with the misfires for about 10-15 seconds on each startup. I had to disconnect and reconnect the intake boot several times before we realized the connectors were reversed.

FYI: The same day, hours earlier, my throttle body was cleaned with various cleaners (deemed safe) by my instructor.

So after the coils connectors were properly reconnected for #4 and #6, the engine started up and seemed to run fine.

A couple of days later, I'm noticing a single engine shake after a short drive with the car stopped in traffic.

I experience it again a day later.

I then took the car on a 3 hour drive a few days later and the shake while stopped is occurring more often. The shake is a single engine shake and it feels like a split second loss in power or a misfire. It may happen 3 or 4 times while stopped for 60 seconds.

Just to provide as much detail as possible, I installed all plugs ( just over hand tight/no torque wrench used) and coil packs on bank 1. Another student, reinstalled both on bank 2.

When tightening down the harness connector, I didn't realize coil connectors were reversed by other student.

My Gcar has just 149,600 miles and I had never experienced anything like this with my engine prior to the work last week. The coil packs all looked great when I had them out.

So this is where I am after having work done to my.car last week.

Any ideas guys on what could be causing the shakes (misfires???)?

Thanks!!!

 

Recheck all your work
Did you use the correct OEM plugs?

Telcoman