fuel additives

[hot37shot]

Are fuel additives ok for emissions systems like the catalitic converters? My truck '99 1500 2wd 5.3L and the cats rattle, but the truck runs fine. No overheating either which would indicate bad cats. Why would my cats rattle ( its definatly the catalitic converters because exhaust hangers and pipes are ok)? Thanks for the info! Shawn

[Falconcbu2]

I use lucas Upper cyl.. additive... works great..

 

That rattling could be your O2 sensor metal caps/clips...

[royg]

The last time i had a cat rattle it ended up clogging the exhaust and truck had no power. It ran fine until you open it up at WOT.

[C & A s Dad]

Most fuel additives are fine. I have discussed this with a tech at Lucas and he promised me their product was not only ok, it acutally helped the em syst work better. Of course they are in the business of selling this stuff.

 

I have used it for several years at every fill up in my work Dodge Carvans and never had one issue. I have also used it in my Yukon XL since I bought it. It will help your MPG but not a significant amount.