Will a Brock FLASH work with a stock or a non-Brock's Performance aftermarket exhaust?

That answer depends upon several factors:

1. Use of any Brock’s Performance ECU flash with stock exhaust: It is not recommended. There are multiple adjustments made in a BrockFLASH ECU flash that are simply incompatible with the stock exhaust and catalyzer. Brock’s Performance is in the ‘competition use only’ performance business. There are many flash options on the market for mild tuning adjustments to smooth out stock bikes… just not from us. Our suggestion? Check to see if Guhl Motors makes a flash for your combination and if so, you are in luck. They are the best in the business as far as Brock’s is concerned. Otherwise, search forums related to your machine and select a reputable flash company. We try to avoid ‘hobby’ tuners as they tend to disappear after a while, leaving you with no support

2. Use of BrockFLASH Stage 1-F with Fuel Tune with other brands of aftermarket full or slip-on exhausts: Please understand that any fuel tuning in the BrockFLASH ECU was developed using the Brock’s Performance exhaust the flash is intended to match. This means that 100% accurate fueling with a non-Brock’s exhaust is simply not possible. Is it ‘good enough’? Many enthusiasts think so. We have many happy riders who use our flash/mapping with our competitor's exhaust with very good results. Our ECU Flash Release Form asks what type of exhaust is on the bike when sending the ECU in to be flashed, so our staff will do our best to select the best flash for your (our customers) application. Be warned – there is no guarantee of performance, drivability, etc… when selecting a non-matching flash.

3. Use of BrockFLASH ECU derestriction and Piggyback fuel tuner (Dynojet PCV, Bazzaz, Rapidbike, etc…) with other brands of aftermarket full or slip-on exhausts: This answer is basically the same as #2 above. The ECU flash itself will be compatible, but the piggyback fuel maps cannot be 100% correct. The bike should be dyno tested by a reputable tuner/tuning center for max performance and drivability. Please note: Brock’s Performance PCV mapping requires a Brock’s Performance exhaust purchase verification. More info. on Brock’s Map Support Program.