Before anyone say anything, yes, these cars shouldn't be speeded but I wanted to see how it performed at high speeds. Car runs super smoothly and quietly even at 110-115 MPH.

Today I ran the car around 110MPH for about 20 seconds. I decelerated and the car was fine. Drove for about two more miles and then check engine light came on. Stopped and restarted the car and light was still on. Exhaust stinks real bad like burnt oil or fuel. No smoking. No weird noises or vibrations. Could this be related to exhaust or fuel system issues? I assume more gas = possibly oxygen sensor issues.

 

It’s just a guess until you retrieve the code(s).

 

Let the car cool down, check engine still on Coolant and oil levels are fine. Accelerated the car and it started spraying water or coolant with black gunk out of the exhaust. The exhaust stinks really bad immediately after revving.
This is what sprayed onto the car parked behind me. (Don't worry, I cleaned it.)

Spraying water or coolant at every rev. AC is off.

 

Will see if my smog guy lets me use his OBD reader tomorrow. But for now, what do you think? It can't be that bad if there's no smoke or shaking or weird noises right?

 

Usually a sign of blown head gasket(s) but it could also be due to moisture condensation in the exhaust (in very humid weather).

 

It's not humid here at all! Probably the blown head gasket then. Is that expensive to repair

 

Yes it its expensive always when it is done right. Before banging your head to the wall, please do basic tests to determine the gasket failure.

These cars are meant to withstand fast speeds., not necessarily track day no.

There is always water when engine is cold and exhaust pipes are cold. Exhaus fumes are moist what condenses to water when pipes are cold. After a really much soft driving and idle pipes have soot what comes out with black water. If coolant gets to the cobustion chamber it will come out white smoke with taste/smell of sweet and tangy. And white smoke may fill the room if the leak is bad when revving.