I removed my stock headers to install a set of Fabspeed headers. When I looked inside of my stock headers, both of them had this white/grey residue/coating inside. One was whiter than the other. The car doesn't smoke and the exhaust tips don't have any of the white coating. My car is a 08 with 9xxx miles, mods are tune, exhaust, clutch and denso plugs. Everything was just installed 300 miles ago except for the exhaust. Car runs fine before and after the tune, no hestiations, misfires..etc. There's no white residue on the exhaust tips. I did run 10 gal of unleaded 100 octane gas before finishing a full tank of 93 last night before the header change. The used Fabspeed headers were black inside in comparison. Does this mean the car is running lean? Should I be worried?

Pics,

 

 

I think thats the 100 octane.. Ive seen tips go white while running c16 but then again thats leaded fuel.

 

I don't have it on the exhaust tips though.

 

If you have catalytic converters it might not get to the tips.

 

Yah, I have 200 cell cats. Will the unleaded 100 kill my cats in the long run?

 

I think what they approve low-leaded and unleaded is very similar... White residue usually occurs from leaded 110+ octane with leaving tail pipes with a film of white residue; 110+ will destroy cats... I guess the 100 your putting in has "low-lead" levels to almost none so they call it unleaded... Your on the island; where do you fill up 100? I only use 1 place off the Southern state exit 17

 

That residue can also get on your O2 sensors and can make them function less than optimal. Make sure the 100 you are using is lead free and not leaded/low lead. 100 octane race "gas" has lead and 100 octane race "fuel" is unleaded. This was inside info from my NHRA drag strip fuel guy.

 

That's the place I use too, I don't know of any other places on the Island.

 

Yes, I use the same gas... out of the same pump; and it is claimed to be 100 octane unleaded... And Sunoco race gas finder sends me there, even though its not a Sunoco gas station. I have heard stories of 100 octane having low levels of lead despite being classified as unleaded. Makes me hesitant to run race gas. 93, and meth when needed sounds like a better alternative.

 

I just ordered a durametric cable, so I can check my AFR just to be safe. But it does seem like it's from the gas.

BTW, I found another spot for 100 octane, it's on Straight path in Wyandanch.

 

yup and also another spot ,off the wantagh .....

 

I heard someone mention that spot before, where is it exactly?