What is a more important criteria to follow when picking out the closest map to your exhaust set up?

For example if I have a 2 into 1 with no close match, but find a 2 into 2 exhaust with the same exact headers I'm running, will that map run good? Or am I still better off using a 2 into 1 map even though though is no close match?

I've heard people tell me that the headers were the most important, but others tell me the the over length vs 2-1/2-2....

 

Nothing?

 

When I look at the map listings for my TMax, it seems that the right map would be based on the 2:1. Maybe I'm wrong but that's the one I would use if I didn't know any better. If it doesn't work well it's easy enough to change maps.

 

What tuner you got? TTS, SEPST? TMax? PV? PCV?

Makes a big difference on how things get picked

 

It's a PC-V...

The engine is stock w/ stage 1 air cleaner.

There is no but lakester 2 into 1 on dynojet's site, but there is a bub lakester 2 into 2. So I can either use that or use another 2 into 1 map w/ a different exhaust.