It'll at least let you see some improvement from your previous times, plus you'll know it'll run a little better once you get it tuned. 
I need some advise?
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From: Tennessee Tech
I need some advise? I installed longtubes on my car not too long ago. It seems to be running fine, except for the usual rich smell associated with the untuned motor. Should I run it in the 1/8 to see what it will run, before and after the tune. I won't be getting a tune for another month. Just curios, I was thinking about testing it tonight.
The stock tune allows for about a 25% variation on fuel tables, right?
So, uh, if your car is still running rich after headers, does that mean you're probably already at -25% on your fuel trims? So, a tuner would adjust your fuel tables to get you more around .000 fuel trims after headers?
In other words, will the engine try and correct itself for running rich up to a certain point? Like, if after headers i'm sitting at -18% fuel trims, is it likely that my engine has already corrected the air/fuel?
So, uh, if your car is still running rich after headers, does that mean you're probably already at -25% on your fuel trims? So, a tuner would adjust your fuel tables to get you more around .000 fuel trims after headers?
In other words, will the engine try and correct itself for running rich up to a certain point? Like, if after headers i'm sitting at -18% fuel trims, is it likely that my engine has already corrected the air/fuel?
Originally Posted by X-JeSSter
The stock tune allows for about a 25% variation on fuel tables, right?
So, uh, if your car is still running rich after headers, does that mean you're probably already at -25% on your fuel trims? So, a tuner would adjust your fuel tables to get you more around .000 fuel trims after headers?
In other words, will the engine try and correct itself for running rich up to a certain point? Like, if after headers i'm sitting at -18% fuel trims, is it likely that my engine has already corrected the air/fuel?
So, uh, if your car is still running rich after headers, does that mean you're probably already at -25% on your fuel trims? So, a tuner would adjust your fuel tables to get you more around .000 fuel trims after headers?
In other words, will the engine try and correct itself for running rich up to a certain point? Like, if after headers i'm sitting at -18% fuel trims, is it likely that my engine has already corrected the air/fuel?
This usually takes about 200 miles of driving, I noticed when I did my headers, the fuel smell was very strong, for about a week, after about 200 miles (my usual weekly mileage) the fuel smell was alot less, and my MPG increased (on the next tank, it went back to 19)
I suspect it's still running rich, but have no way of determining what the actual a/f ratio is (no scanner or tuner)
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Ah, I borrowed my buddy's microchips scanner and my fuel trims were right at about .0, so I assume I've definitely got some leeway after I put headers on. Can the O2's in the manifolds report an air/fuel mixture, or do you need wideband for that? I assume they have to know something about air/fuel if they help the PCM tune the mixture out, don't they?
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