I put a roland sands 2into1 exhaust on my '14 sportster that had the stage 1 air cleaner & retune done, I've run it about 30 miles and it ran great but i'm worried that I could hurt something or throw a code by it running too lean. does it need to be reprogrammed or does it adjust itself for less backpressure?

 

If you went from the OEM Sportster exhaust to the RS 2 into 1 yeah, you need to re-tune the bike.

 

Your bike's ECU is designed to let your stock bike run through deserts and Alaskan winters, from sea level to the highest mountain pass, but not to compensate for changing stuff! It will thank you for being retuned to match your changes.

 

If you already have the Stage 1 map flash (re-tune) from the dealer when you upgraded the air cleaner then you should be ok. If you want to fine tune or dyno tune the bike then get an aftermarket tuner.

 

If that 2:1 works half ways decent, it's going to surpass any gains from that canned dealer flash. The stage 1 flash doesn't do much, IMO I'd tune it.