check engine light
Thread Starter
Le Mans Master
Joined: Oct 2008
Posts: 8,891
Likes: 981
From: Whitby Ont.
check engine light
I know this topic as been 
, I put headers on last week,and have run it about 100 miles or so, now,yesterday the check engine light comes on,if I do the code procedure thing, I get lots of numbers and codes and things, that don t mean to much to me, do I have to write all the codes down then come back here somewhere and look each one up ? some have a c,some a h, some both. or just disconnect the battery for a few minutes and hook back up ?
, I put headers on last week,and have run it about 100 miles or so, now,yesterday the check engine light comes on,if I do the code procedure thing, I get lots of numbers and codes and things, that don t mean to much to me, do I have to write all the codes down then come back here somewhere and look each one up ? some have a c,some a h, some both. or just disconnect the battery for a few minutes and hook back up ?
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,143
From: Dyer, IN
I assume this thread is soliciting the forum for help. There are a myriad of things that will precipitate a check engine light. If you don't post the specific codes, how can anyone help you?
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
Long tube headrs are great !! however you will ALWAYS get codes---
Reason being the 02 bungs are further back then they were in the stock locations--This causes your ECM to get false 02 readings--also causes your 02's to not heat up correctly---also may cause your rear 02's to report false cat issues
Good news is that tuning can fix it all---These 02 related codes must be permanently deleted from your tune---A handheld tuner won't do--You'll need a full tuner like HP or EFILIVE--
PS: often times with LT's you may even make LESS HP until you get it tuned--as you won't get the full benefit of the LT's without one---That's why they are illegal in most states !!
Reason being the 02 bungs are further back then they were in the stock locations--This causes your ECM to get false 02 readings--also causes your 02's to not heat up correctly---also may cause your rear 02's to report false cat issues
Good news is that tuning can fix it all---These 02 related codes must be permanently deleted from your tune---A handheld tuner won't do--You'll need a full tuner like HP or EFILIVE--
PS: often times with LT's you may even make LESS HP until you get it tuned--as you won't get the full benefit of the LT's without one---That's why they are illegal in most states !!
Thread Starter
Le Mans Master
Joined: Oct 2008
Posts: 8,891
Likes: 981
From: Whitby Ont.
check engine light
Long tube headrs are great !! however you will ALWAYS get codes---
Reason being the 02 bungs are further back then they were in the stock locations--This causes your ECM to get false 02 readings--also causes your 02's to not heat up correctly---also may cause your rear 02's to report false cat issues
Good news is that tuning can fix it all---These 02 related codes must be permanently deleted from your tune---A handheld tuner won't do--You'll need a full tuner like HP or EFILIVE--
PS: often times with LT's you may even make LESS HP until you get it tuned--as you won't get the full benefit of the LT's without one---That's why they are illegal in most states !!
Reason being the 02 bungs are further back then they were in the stock locations--This causes your ECM to get false 02 readings--also causes your 02's to not heat up correctly---also may cause your rear 02's to report false cat issues
Good news is that tuning can fix it all---These 02 related codes must be permanently deleted from your tune---A handheld tuner won't do--You'll need a full tuner like HP or EFILIVE--
PS: often times with LT's you may even make LESS HP until you get it tuned--as you won't get the full benefit of the LT's without one---That's why they are illegal in most states !!
thanks Al
Thread Starter
Le Mans Master
Joined: Oct 2008
Posts: 8,891
Likes: 981
From: Whitby Ont.
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Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
AFR instead of the Stoich 14.68
But its really not that noticeable and not a big deal--
Noone knows 100% xactly how to correct the fuel back to 14.68--But I have had some good results by--
Lowering the 02 switching point table
installing the rear 02's onto the front location
leaning out the "commanded open loop table normal" ( for cold starting)
leaning out the VE table in the cruiseing RPM ranges
commanding a leaner closed loop fuel to trick the ECM
problem is that today's 02's have a very narrow band as to where they take accurate readings----That is around .450 millivolts or 14.68-1 AFR
Even if you try to command an AFR leaner like 14.98 to correct a 14.38 actual AFR ( wideband verified)
it beomes out of the " accurate" range of the narrowband 02
But if you are in a no smog roller state its OK--Again that's why LT's are illegal in many states as they dump more HC's into the air with a richer than needed AFR