This is a common question for us at ModernPerformance.com.
Customers with 2003/2004/2005 Dodge SRT-4’s will add an air intake, downpipe, exhaust, turn up the boost with a boost controller, or other minor mod and think they have to tune for each mod.
Whenever customers think they need a tune for each mod, it means one of two things for us: 1) These are new owners that have never modified a car before and are just being precautious 2) These customers previously owned a Subaru, Toyota, Chevrolet, Ford, etc car that uses a mass air flow sensor.
All cars use either a Mass air flow sensor or a speed density map pressure sensor type sensor to determine how much air is flowing into the motor. In the photo below you can see a mass air flow sensor on a 2008-10 Chevrolet Cobalt SS Turbo.
For cars with mass air flow sensors, they cannot accurately adjust for changes made, and so generally they will require a new computer tune for each mod done (intake, exhaust, downpipe, intercooler, etc).
For cars with map sensors like just about every Chrysler made, they will automatically adjust for each mod you do and for the most part dont need a tune unless you do a major mod like change injectors or change the turbo.