NG900 & OG9-3 Workshop
I have a 1999 Saab 93.
I occasionally get a P0303 code when driving on highways (typically).
I just changed the plugs using the NGK recommended and gapped to .04.
Here is the freeze frame data...
Dtcfrf..........P0303
Fuelsys1......CL
Fuelsys2......NA
Load%.........24.7
ETC.............201...