Most common issue with header installs. A scanner will tell the story.
Installed Headers, Engine runs rough
Thread Starter
Instructor
Joined: Feb 2023
Posts: 136
Likes: 14
From: Plainfield, IL
Installed Headers, Engine runs rough
My son has a 2001 Coupe, manual. He installed Speed Engineering headers and y pipe and he already had a Corsa cat back. Now the engine runs like it is missing on 1 or 2 cylinders.
Any thpoughts?
Any thpoughts?
Heel & Toe
Joined: Apr 2025
Posts: 20
Likes: 5
From: Mcallen, TX
Check to see if you broke a spark plug, that porcelain is very brittle
Thread Starter
Instructor
Joined: Feb 2023
Posts: 136
Likes: 14
From: Plainfield, IL
Plugs were out when header installed. I did tell him how important it was to use a spark plug socket with the rubber boot inside. and how brittle porcelain is. The AIR is disconnected and has been tuned out of the system so no codes pop up on the DIC.
actually, it runs good for the first 2 minutes then runs rough.
actually, it runs good for the first 2 minutes then runs rough.
Heel & Toe
Joined: Apr 2025
Posts: 20
Likes: 5
From: Mcallen, TX
Plugs were out when header installed. I did tell him how important it was to use a spark plug socket with the rubber boot inside. and how brittle porcelain is. The AIR is disconnected and has been tuned out of the system so no codes pop up on the DIC.
actually, it runs good for the first 2 minutes then runs rough.
actually, it runs good for the first 2 minutes then runs rough.
Last edited by rob3eli; May 14, 2025 at 02:59 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
Good order in what respect? If you cannot read the O2s, how do you know they are good, or at the very least how they are responding? 12v and ground checks? What extension harnesses were used?
Thread Starter
Instructor
Joined: Feb 2023
Posts: 136
Likes: 14
From: Plainfield, IL
In the next day or two it will be hooked up to a scanner and then we will be able to see the functionality of the o2 sensors. I think they are good visually as when they were removed and installed care was taken to make sure nothing was broken, bent, etc.
The o2 extension was purchased from Speed Engineering, I believe.
The o2 extension was purchased from Speed Engineering, I believe.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Tech Contributor
Joined: Jan 2007
Posts: 19,465
Likes: 1,167
From: Dyer, IN
In the next day or two it will be hooked up to a scanner and then we will be able to see the functionality of the o2 sensors. I think they are good visually as when they were removed and installed care was taken to make sure nothing was broken, bent, etc.
The o2 extension was purchased from Speed Engineering, I believe.
The o2 extension was purchased from Speed Engineering, I believe.
1) Make sure the front O2s are not crossed....so drivers side to left, and passenger side to right. The wire colors almost are identical except bank 1 (left) has a white stripe on the heater circuit wires.
2) Make sure the extension harnesses are pinned up correctly
3) 12 volt and ground checks
