Hey guys -

I've noticed that my rear bumper and exhaust tips seem to have a light coating of exhaust dust. My friend thinks it means my car is running a little rich. Is there something I need to do? I am running the decaf CA fuel (91 Octane). I seem to have read in Sport Compact Car Mag that they had a similar problem with their Evo, so I'm hypothesizing that its because the F20c was designed for a higher octane level than we get in CA and the ECU is running it a little richer - thus depositing some soot on my rear bumpers. Any advice would be welcome.

-Luke

 

1) is this normal? The tips of the exhaust are not going to be squeeky clean.

2) 91 octane is normal. Yes, some parts of the country have higher octane ratings commonly available, but 91 is fine.

3) the cat is supposed to burn up the unburned hydrocarbons. Perhaps yours is bad?

 

It's not a lot...and if that cat was bad, my CEL would come on...and I, of cource forgot to mention this at my last service, last week...