How fix 502.3 error for ASP.NET app

[eyerusy]

one operation in our asp.net app is causing a HTTP 502 error right at 2 minutes of server side code running. failed request tracing confirms it's a timeout error (502 3). we've tried increasing executionTimeout on httpRuntime element to no avail. we believe the code does some sql queries then iterates through data - for now we just want to bump up the timeout so the app continues to run - any ideas which timeout setting we need to increase? @[Application Development] @[Technology Infrastructure] #urgent btw, we've duplicated this in our test environment