C5Z rough idle after start
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Without actually seeing the LTFT data and the O2 sensor outputs (in closed loop)you are not really going to be able to accurately solve this issue without throwing LOTS of parts and money at the issue.
Get the scan tool, learn how to set it up. You will most likely have to select "PIDs" to display the LIVE DATA that you need to examine. The instructions will tell you how to do that.
Bill
Get the scan tool, learn how to set it up. You will most likely have to select "PIDs" to display the LIVE DATA that you need to examine. The instructions will tell you how to do that.
Bill
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,633
Likes: 4,079
From: Cape Coral, Florida
Without actually seeing the LTFT data and the O2 sensor outputs (in closed loop)you are not really going to be able to accurately solve this issue without throwing LOTS of parts and money at the issue.
Get the scan tool, learn how to set it up. You will most likely have to select "PIDs" to display the LIVE DATA that you need to examine. The instructions will tell you how to do that.
Bill
Get the scan tool, learn how to set it up. You will most likely have to select "PIDs" to display the LIVE DATA that you need to examine. The instructions will tell you how to do that.
Bill
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,633
Likes: 4,079
From: Cape Coral, Florida
I believe my C5Z comes Stock with 4 02 sensors. Looks to me like the previous owner capped the 2 that are in the middle of the exhaust. I still have the 2 closest to the headers. I also noticed that the wiring is still there for both sensors not being used but they have some type of black block plugged in to them. This car has headers, not cats, 2 O2 sensors, and the original Tit.. mufflers. Can this be the reasons for a rough idle at start and gassy smells from the exhaust. Checked injectors and they are not leaking. I did get a check valve code.
