spark plug reading

[watchamakalit]

Changed my plugs today. Anything stand out to anyone?  If memory serves these have about 20,000mi on them.

 

[89 MJ]

They look pretty good. A little lean, but that’s the way these trucks run. 

[watchamakalit]

A little lean is surprising. I ran a flowmaster with no cat for a good bit of those miles and I thought it always seemed a little rich.

[89 MJ]

2 hours ago, watchamakalit said:

A little lean is surprising. I ran a flowmaster with no cat for a good bit of those miles and I thought it always seemed a little rich.

Mine doesn’t have a cat either. It runs lean too. 

[Parei_doll_ia]

On 9/3/2021 at 5:21 AM, watchamakalit said:

A little lean is surprising. I ran a flowmaster with no cat for a good bit of those miles and I thought it always seemed a little rich.

Free-er flowing exhaust without tuning to add more fuel will cause any FI system to run lean. It's not a big difference though, and your plugs are fine.