Header Removal---Issues?
Thread Starter
Racer
Joined: Apr 2005
Posts: 443
Likes: 101
From: Jackson CA.
Header Removal---Issues?
I am removing a set of LG headers from my 2000 supercharged C5 and returning exhaust to stock due to selling my car and it will not pass visual smog here in good old California. Also putting the H-pipe back on. Of course I had the car tuned when I put the S/C on, and it was tuned again when I put the headers on. Will I have issues placing the stock exhaust back on without a tune? Appreciate any help.
Thread Starter
Racer
Joined: Apr 2005
Posts: 443
Likes: 101
From: Jackson CA.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Depends on what you or your tuner did to correct the fueling using the front 02 sensors or left it all stock---Most tuners with LT's will adjust the 02 switching points to a lower value to trick the ECM into a P/T fueling back to the Stoich value of 14.68-1--- Typically LT's will make your engine run very rich at P/T because the front 02's are moved so much further back that they do not read correctly -Normally like in the 11's or 12's
I would 1st try after installing the stock manifolds and seeing what your 02's are averaging at idle and P/T Ideally you want them to have an average between .400 and .500 Millivolts LT's make the averages go way up .600 and more A larger number average means a RICHER P/T fueling
If the averages are betwwen .440 and .500 you are golden But if the tuner altered the 02 switching points Now your P/T and idle fueling will be way LEAN !! Then just put the stock switching point values back to stock
None of this as anything to do with boost or WOT fueling---Just start up---idle-- and pre boost P/T driving
I would 1st try after installing the stock manifolds and seeing what your 02's are averaging at idle and P/T Ideally you want them to have an average between .400 and .500 Millivolts LT's make the averages go way up .600 and more A larger number average means a RICHER P/T fueling
If the averages are betwwen .440 and .500 you are golden But if the tuner altered the 02 switching points Now your P/T and idle fueling will be way LEAN !! Then just put the stock switching point values back to stock
None of this as anything to do with boost or WOT fueling---Just start up---idle-- and pre boost P/T driving
