Ignition - Spark Plug Information

Number 85-6(Gasoline)-12 Date 1/85
Subject: SPARK PLUG INFORMATION ON 1985 SUNBIRD MODELS WITH OHC-FI ENGINES - CODE O..
Some published information from sources other than Pontiac indicate that the copper tip spark plug #R44CXLS (GM #8990424) is a direct replacement for the Standard #R44XLS (GM #8990440).

In some engines this may be true. However, testing in the 1.8L OHC-FI, (engine code O), indicates some degree of performance may be lost as a result of using the #R44CXLS plug.

Pontiac is therefore, not recommending the use of the #R44CXLS in its 1.8L OHC-FI engines.

NOTE: The #R42CXLS plugs used in 1.8L MPFI engines, (Code J) are not affected.