UEL headers = black soot on exhaust tips?
 

Hey everyone,

I installed OFH and OFT Stg2 93 tune on my FR-S a while ago, and now I'm noticing black soot on my exhaust tips.
Being catless, it would make sense to me that this happens because some of the exhaust isn't being put thru a cat...
But could it also be that I'm running rich? I know unburnt gas will cause this soot.

So, anyone with catless headers also seeing this, or do I need to get my tune checked?

Thanks everyone!

My guess would be that she's a tad on the rich side.

Catless and running rich will definitely do that. You're using the stage 2 tune so this mean that you will be running richer for safety reasons. No one wants to run lean and running richer is the better option.

I wouldn't worry about it too much bud, just have to clean you're exhaust tips a little more often :thumbsup:

Well, the good news is that you don't have a white car. On my 2014 Evo, I had to tune to the rich side of things as I had full exhaust and a bunch of other goodies. The whole back end of my car was speckled with carbon within 10 minutes of driving it. I really thing that was the main reason I sold it.. LOL

Theres a pair of turbo'd FRS's that are local and whenever I see them they're covering in black soot on the rear bumper for having to run richer with the turbo setup.

Since you're running a OFT, you can log many engine parameters to check to see if you're running lean/rich AFRs. I'd recommend doing that first (cause it's easy and fast). You can even post your log on datazap for others to review. Chances are nothing is wrong, but it never hurts to look.

running rich is A OK! haha, dont worry about it man

Thanks everyone for your responses!
I guess it's okay I'm running rich, I will keep an eye on my OFT but I'm not too worried about it.

If you're worried datalog and post the logs to datazap.me and post them here we can check them out.

Some people like to say that tuning is 75% science and 25% art.

I usually tell them no, silly, 25% is just where your fuel trim pegs out.

:lol:

Don't worry about it. The OFT tunes all run pretty rich, but say what you want about them, they're safe and reliable. As long as your fuel trims aren't all over the place, you have nothing to worry about.

If LTFT is a mess, you have a bit of work to do.

TLDR soot is normal on any of the tuning shiv put out on the OFT.

You have an OFT. log your afr. Much more accurate at reading you fuel mixure than trying to read the soot on your tailpipe. ;)

Yep logging is easy and is the best way to figure out if you're running rich. FWIW with my JDL UEL header/OFT combo, I do notice some black soot buildup on my rear bumper and exhaust tips. My logs indicate I'm running slightly rich (although not too far off commanded AFR).