2014 Z28 Error Code P0305 All of a sudden - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

JRowe500 · 10-16-2022, 03:07 PM

I took my Z out for a nice Sunday ride and the check engine light started flashing and the check Stability light came on. Seems like at the same time. The car doesn't even have 3,000 miles on it.

My OBD2 reader tells me that it is a misfire on number 5 which according to the firing order would be cylinder number 6. Anybody have the experience?

I guess it could be a bad coil pack, spark plug, lifter, plug wire. Who knows. The car is stock.

I know this is not the right area to post but I was wondering if anybody with a Z28 had the same issue.

69L48Z27 · 10-16-2022, 06:04 PM

No idea why at 3000 miles you got that. Why is cylinder 5 really #6? I always thought misfire codes were telling you want cylinder the problem was and not firing order position.

I would swap the coil pack, check the plug. Clear codes and try again. Coil pack, plug, wire or injector are typically what causes misfire.

Did the car start running different or rough?

608RS · 10-16-2022, 06:13 PM

still on original battery? if the car drops below 12v while driving that can also happen and it could be possible your battery is gone. setup your dash to show current battery voltage and see if it drops below 12v while driving

JRowe500 · 10-16-2022, 06:32 PM

Quote:

Originally Posted by 69L48Z27

No idea why at 3000 miles you got that. Why is cylinder 5 really #6? I always thought misfire codes were telling you want cylinder the problem was and not firing order position.

I would swap the coil pack, check the plug. Clear codes and try again. Coil pack, plug, wire or injector are typically what causes misfire.

Did the car start running different or rough?

Car is running rough. From what I read the P0305 code means the 5th cylinder in the firing order which would make it the 6th cylinder. Correct me if I am wrong.

JRowe500 · 10-16-2022, 06:33 PM

Quote:

Originally Posted by 608RS

still on original battery? if the car drops below 12v while driving that can also happen and it could be possible your battery is gone. setup your dash to show current battery voltage and see if it drops below 12v while driving

It is the original battery, I will check that.

Thanks

pzero · 10-17-2022, 06:00 AM

Check all the spark plug wires, make sure they’re on tight. One of them might be loose. Has happened to me once. Good luck and let us know what you find out.

Coz3z3 · 10-17-2022, 08:22 AM

Quote:

Originally Posted by JRowe500

Car is running rough. From what I read the P0305 code means the 5th cylinder in the firing order which would make it the 6th cylinder. Correct me if I am wrong.

P0305 means misfire on Cylinder 5. Never heard of it the way you have described regarding the firing order. Should be the actual cylinder though. So cylinder 5.

JRowe500 · 10-17-2022, 11:17 AM

Quote:

Originally Posted by Coz3z3

P0305 means misfire on Cylinder 5. Never heard of it the way you have described regarding the firing order. Should be the actual cylinder though. So cylinder 5.

I just read that online somewhere. Seems like it would just mean the cylinder and not the firing order.

Thanks

Coz3z3 · 10-17-2022, 11:27 AM

Interesting. Hopefully an easy fix for you! Keep us posted!

1erMQP · 10-18-2022, 02:40 AM

Had the same issue two years ago. The plug wire got loosened in the coil pack. Was easy to fix by turning the plug wire propper in the coil pack. No issues since then.

JRowe500 · 10-18-2022, 05:40 AM

Quote:

Originally Posted by 1erMQP

Had the same issue two years ago. The plug wire got loosened in the coil pack. Was easy to fix by turning the plug wire propper in the coil pack. No issues since then.

I checked that but will check again. Did you have the stabilli trak code too?

1erMQP · 10-18-2022, 06:05 AM

Quote:

Originally Posted by JRowe500

I checked that but will check again. Did you have the stabilli trak code too?

Yes

102SS · 10-18-2022, 07:29 AM

Bank 1 DS is 1357

Bank 2 is PS 2468

Try changing the wire from 3 to 5 and 5-3 to see if that fixes it

Then change the plugs next if its still on 5

Then swap the coils

Then swap the injectors

If its still on 5 its more than likely mechanical and its time to pull the valve cover for a peak

JRowe500 · 10-18-2022, 06:30 PM

Quote:

Originally Posted by 102SS

Bank 1 DS is 1357

Bank 2 is PS 2468

Try changing the wire from 3 to 5 and 5-3 to see if that fixes it

Then change the plugs next if its still on 5

Then swap the coils

Then swap the injectors

If its still on 5 its more than likely mechanical and its time to pull the valve cover for a peak

Thanks I will try that.

I Googled the code and read somewhere that it is not cylinder number 5 but the 5th cylinder in the firing order. Have you ever heard of that? Most places I have read never mention the firing order.

10-16-2022, 03:07 PM	#1
JRowe500 Drives: Camaro z28 Join Date: Mar 2021 Location: Clermont Posts: 74	2014 Z28 Error Code P0305 All of a sudden I took my Z out for a nice Sunday ride and the check engine light started flashing and the check Stability light came on. Seems like at the same time. The car doesn't even have 3,000 miles on it. My OBD2 reader tells me that it is a misfire on number 5 which according to the firing order would be cylinder number 6. Anybody have the experience? I guess it could be a bad coil pack, spark plug, lifter, plug wire. Who knows. The car is stock. I know this is not the right area to post but I was wondering if anybody with a Z28 had the same issue.

10-16-2022, 06:13 PM	#3
608RS Drives: 2015 2ss Join Date: Jun 2009 Location: Carol Stream IL Posts: 638	still on original battery? if the car drops below 12v while driving that can also happen and it could be possible your battery is gone. setup your dash to show current battery voltage and see if it drops below 12v while driving __________________ 2015 Camaro 2ss, NicKey Performance built/tuned

10-18-2022, 07:29 AM	#13
102SS waiting at the tree Drives: SIM 2010 2SS/RS A6 Join Date: Apr 2013 Location: Niagara Falls Posts: 3,132	Bank 1 DS is 1357 Bank 2 is PS 2468 Try changing the wire from 3 to 5 and 5-3 to see if that fixes it Then change the plugs next if its still on 5 Then swap the coils Then swap the injectors If its still on 5 its more than likely mechanical and its time to pull the valve cover for a peak __________________ 2010 2SS/RS A6 ZL1 Rims 60ft 2.03 13.08 at 107.82 (4/28) 2009 Pontiac G8 3.6L the DD

10-16-2022, 06:04 PM	#2
69L48Z27 Drives: 2015 Z/28; 1969 Camaro SS Join Date: Nov 2015 Location: York, PA Posts: 805	No idea why at 3000 miles you got that. Why is cylinder 5 really #6? I always thought misfire codes were telling you want cylinder the problem was and not firing order position. I would swap the coil pack, check the plug. Clear codes and try again. Coil pack, plug, wire or injector are typically what causes misfire. Did the car start running different or rough?

10-17-2022, 06:00 AM	#6
pzero Drives: 2015 Camaro Z/28 #968 Silver Ice M Join Date: May 2019 Location: Houston Posts: 365	Check all the spark plug wires, make sure they’re on tight. One of them might be loose. Has happened to me once. Good luck and let us know what you find out. __________________ Current Cars: 2008 Honda CRV 2.0L 2015 Chevy Z/28 7.0L 2016 Chevy Tahoe 5.3L Past Cars: 1976 Chevy Malibu Classic 5.7L 1985 Chevy 2DR 4x4 Blazer 5.7L 1989 Chevy IROC-Z 5.7L 1995 Chevy 2DR 4x4 Tahoe 5.7L 2005 Chevy 4DR Tahoe 5.3L

10-17-2022, 11:27 AM	#9
Coz3z3 Drives: 2015 Z/28, 2015 1LE Join Date: Feb 2017 Location: Nevada Posts: 583	Interesting. Hopefully an easy fix for you! Keep us posted!

10-18-2022, 02:40 AM	#10
1erMQP Drives: 15 Z/28 #605 Join Date: Aug 2017 Location: Germany Posts: 47	Had the same issue two years ago. The plug wire got loosened in the coil pack. Was easy to fix by turning the plug wire propper in the coil pack. No issues since then.