Heated O2 sensor not going closed loop
Thread Starter
Drifting
Joined: May 2002
Posts: 1,509
Likes: 3
From: Hazel Park MI
Heated O2 sensor not going closed loop
on the expressway at all. 85 4+3. I have the EM ceramic headers. Around town it goes closed loop. I have an Ed Wright chip not calibrated for the headers, or the large tube runners and siamesed base for that matter. Will chip retuning help, or do I just have to deal with the drop in mileage? Thanks! 
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Good question.
Also, are you sure that the O2 sensor is wired properly and really heating the sensor. On the highway it may well be cooling off if the heater is not functioning.
Where in the header setup is the O2 sensor bung located??
If you are checkig with a scan tool, does the O2 sensor still swing between .3-.9 Vdc on the highway?
Also, are you sure that the O2 sensor is wired properly and really heating the sensor. On the highway it may well be cooling off if the heater is not functioning.
Where in the header setup is the O2 sensor bung located??
If you are checkig with a scan tool, does the O2 sensor still swing between .3-.9 Vdc on the highway?
Thread Starter
Drifting
Joined: May 2002
Posts: 1,509
Likes: 3
From: Hazel Park MI
Coolant temps never get above 190, especially on the highway. I used the tech tip heated O2 sensor conversion, the bung is located on the driver's side collecting tube. I have an antiquated scan tool (monitor 4000), and for some reason it doesn't show the O2 voltage. I'm using the field service mode test from the shop manual - and the check engine light is blinking twice a second, at least! I re-checked my wiring and things - it seems to be good, but I may have to use the O2 test in the shop manual to really determine what is going on. Maybe I bought a bad connector or sensor? Oops, how stupid of me to not mention I'm getting the check engine light with the O2 sensor code.
Last edited by jmrl98; Jul 7, 2005 at 03:52 PM.
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Originally Posted by jmrl98
on the expressway at all. 85 4+3. I have the EM ceramic headers. Around town it goes closed loop. I have an Ed Wright chip not calibrated for the headers, or the large tube runners and siamesed base for that matter. Will chip retuning help, or do I just have to deal with the drop in mileage? Thanks!
Have you a way to read your chip? Probably for an error you have the temp to enable closed loop too high. I really don't think it is the problem but I'm just trying to help you to diagnose the problem.
-Beppe-
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
