Should I seafoam my truck?

[T4Rscott]

Hi all,

I have about 143,000 miles on the 4Runner. I have noticed lately that my engine is pinging when pulling a hill just before the transmission downshifts. I know that it is caused somewhat by the winter gas. Should I Seafoam it using the gas tank or the intake method? Also, does Seafoam always foul plugs and O2 sensors? I just replaced my plugs.

I have been using Marvel Mystery Oil every other fill up. Is Seafoam more aggressive?

Thanks for any info.

 

[BrianSD_42]

If it runs fine then leave it alone.

 

[PitbullRescuer]

If you just changed the plugs I'd say leave it alone. Should've Seafoamed it prior to changing the plugs.

 

[LittleCaesar]

Try some premium octane and see if that cures the problem.