Audi A3 2.0L FSI 8P Rough Idle with P1340 Fault Code - How to Fix Timing Issues?

P1340 indicates a mismatch between the crankshaft and camshaft position sensor signals, meaning the engine's timing at Top Dead Center (TDC) for both crank and cam is out of sync. This can occur if the timing belt has been incorrectly adjusted or if components like the camshaft have been moved — such as shifting the cams one tooth forward — which may improve idle but cause a 'P1340-001' fault when detected by VAG COM. Ensure TDC is properly verified using the manufacturer's procedure before reassembly.

Thanks for the clarification. I did move the cams one tooth forward, which initially improved idle smoothness and low-end response. However, after checking with VAG COM, it flagged an 'advanced' cam position error. I then reverted to original timing, and confirmed TDC alignment is correct — still experiencing rough idle at idle speed. Any further diagnostics or checks for sensor issues?