October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.
Exhaust Backfire
Engine not tuned to specifications.
Engine vacuum leaks.
Faulty diverter valve or check valve.
Electric air switching valve or air control valve not switching air pump discharge to air cleaner during engine starting or deceleration.