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

Check for engine vacuum leaks and/or engine not tuned to specifications.
Check for faulty diverter valve or check valve.
Check for electric air switching valve or air control valve not switching air pump discharge to air cleaner during engine starting or deceleration.