Can I use an ATLAS OTS map with an intake or other aftermarket parts?

Only if the map was built for the hardware you actually have, and this is the single most important rule about using any prepared map on any platform. An off-the-shelf or base map is written for a defined configuration - stock, stock plus a specific intake, a particular stage with named parts. The map assumes that hardware and the airflow it produces. Running it on a car that does not match is not a small compromise, it is a map operating on assumptions that are false. The intake case is the sharp one because of how the FA24 works. The ECU calculates fuel from what the mass airflow sensor reports, and an intake with a larger-than-stock MAF housing under-reports airflow. Testing on the VB has shown air/fuel ratios leaning toward 12:1 at the top of the rev range when an oversized-housing intake runs on a map that assumes stock airflow. Lean under boost is the condition that damages engines. So the practical rules: **Read the map notes and match them item by item.** Not approximately, not close enough. If the map names a specific intake, that is the intake it was developed with. **Know your MAF housing diameter.** Some intakes are deliberately built to stock housing dimensions specifically so no retune is needed. Those genuinely can run on a stock-airflow map. Anything with a larger housing cannot. **Parts that do not affect airflow measurement are fine.** An intercooler, a charge pipe, a cat-back exhaust or a turbo inlet do not change what the MAF reports, so they do not invalidate a map. You can run those with any appropriate map. **When your combination stops matching any available map, you need a custom tune.** That is the honest signal to move from off-the-shelf to an e-tune or pro tune rather than picking the closest map and hoping. ATLAS makes this easier to reason about than most platforms, because you have direct access to the tables and can see what the map actually expects. But access is not a substitute for matching hardware, and the fastest way to get into trouble is assuming a capable tool makes an inappropriate map safe.