LT headers do I need a tune?
02-15-2015, 04:47 PM
#11
Formerly ScreamingL
logical? you want logical? are you sure you can handle logical?
what happens when you free up the restrictions? when you answer that you will get the answer as to your logical question
02-15-2015, 06:06 PM
#12
How about because your fueling will change... Or because COT needs disabled so it doesn't needlessly dump fuel, or that 02 switch points may need changed depending on headers and if 02's heat up enough to switch properly.
This thread wasn't created to find out what needed changed in tune, it was created to answer if the tune should be changed for the headers or not. Yes it should, don't rush it. Do it right.
01ssreda4- you said it's not advised, how about you share your reason also since you pointed that out.
This thread wasn't created to find out what needed changed in tune, it was created to answer if the tune should be changed for the headers or not. Yes it should, don't rush it. Do it right.
01ssreda4- you said it's not advised, how about you share your reason also since you pointed that out.
Last edited by 03sierraslt; 02-15-2015 at 06:12 PM.
02-15-2015, 06:21 PM
#13
While what you stated is largely true none of those are reasons why he "can't" run without tuning. As long as he doesn't mind the CEL it's not going to damage anything. I ran without a tune for a little (while a day or so)and it was just fine. That said of course it is a much better choice to get the truck tuned as quick as possible.
02-15-2015, 06:54 PM
#14
Formerly ScreamingL
While what you stated is largely true none of those are reasons why he "can't" run without tuning. As long as he doesn't mind the CEL it's not going to damage anything. I ran without a tune for a little (while a day or so)and it was just fine. That said of course it is a much better choice to get the truck tuned as quick as possible.
Pat gives you a professional reply, i give the dick reply when questioned.....
ive saw on dyno where a person dyno'd truck stock, then dyno'd truck with headers no tune and was down on power
in a stock truck that doesnt see PE ever in its WOT life, tossing headers on can cause it to go leaner thus possibly hurting the motor or making it live on the knock sensors to pull the timing so it doesnt hurt it
02-15-2015, 10:07 PM
#16
This is good information. Thanks Pat for giving some logical reasons as to why the tune would be off after a header install. I installed headers over Christmas break and am waiting for Justin to come back to DFW for the retune. I am not hard on my truck at all daily driving so I haven't had any issues yet but this helps solidify in my mind that I definitely need the retune before I beat on it at the track.
02-16-2015, 11:28 AM
#17
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I don't tune but... Before my cam I ran my headers open for a weekend till the exhaust shop opened up on Monday, and then drove the truck for a week or two till I was able to get a tune. My mpgs went to 
during that time and the motor idle a little rough at stop lights. The PCM was adding way more fuel than needed b/c it was confused with the headers and rear O2 sensors out of wack.
Plus I noticed a big difference after the tune. My motor was stock besides shorty headers, CAI, and tune. After the longtube swap the truck gained 17rwhp and 13ftlb with an 11ftlb average increase. Longtubes for the win!
during that time and the motor idle a little rough at stop lights. The PCM was adding way more fuel than needed b/c it was confused with the headers and rear O2 sensors out of wack. Plus I noticed a big difference after the tune. My motor was stock besides shorty headers, CAI, and tune. After the longtube swap the truck gained 17rwhp and 13ftlb with an 11ftlb average increase. Longtubes for the win!
02-16-2015, 01:38 PM
#18
It would be a good idea to atleast have your tune looked over after the headers. I added headers a little while after my cam swap, and from the data logs I sent out, my tune needed no additional tweaks as everything was still spot on.
This is with the Ebay 1-3/4 headers and 2.5" ORY. I have not sent in a new data long since adding a 3" catback to replace my 2.5" stuff.
This is with the Ebay 1-3/4 headers and 2.5" ORY. I have not sent in a new data long since adding a 3" catback to replace my 2.5" stuff.
02-16-2015, 04:33 PM
#19
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The Gen 3 engines were introduced in 97. The first tuning solution, LS1 Edit was introduced in I believe 2002. I bought HP Tuners in 04 shortly after it was introduced. Does everyone think these vehicles weren't being modded and run hard those 5 or 6 years with headers, cams, and heads during that time? About all there was to tune them during that time was a MAF translator and O2 sims for the rears. And you worry about driving a vehicle untuned for a few days or weeks without tuning. With MAFs and fuel trims you will not hurt anything. Stock WOT fueling is commanded so rich on just about every GM vehicle, especially trucks, that even a little leaning out won't hurt anything. As long as you don't try and run in closed loop with open headers you will be fine. And if you do need to run open headers for a while, at least unplug the front O2s so it stays in open loop.
02-16-2015, 04:48 PM
#20
Formerly ScreamingL
The Gen 3 engines were introduced in 97. The first tuning solution, LS1 Edit was introduced in I believe 2002. I bought HP Tuners in 04 shortly after it was introduced. Does everyone think these vehicles weren't being modded and run hard those 5 or 6 years with headers, cams, and heads during that time? About all there was to tune them during that time was a MAF translator and O2 sims for the rears. And you worry about driving a vehicle untuned for a few days or weeks without tuning. With MAFs and fuel trims you will not hurt anything. Stock WOT fueling is commanded so rich on just about every GM vehicle, especially trucks, that even a little leaning out won't hurt anything. As long as you don't try and run in closed loop with open headers you will be fine. And if you do need to run open headers for a while, at least unplug the front O2s so it stays in open loop.
during first few yrs of the motors being around alot were posted up as being hurt