[vipermagic]

Ive got an 05 STI with 33,000 miles. Only mods are turboback exhaust and a boost controller, running actually slightly less than stock boost.


Today I decided to take it to the autocross, and while cruising around the paddock i notice that it wont maintain speed... it feels like its accelerating and coasting, over and over, in about 2 second intervals. It also hunts around at idle, never settling on a particular speed. If i turn the AC on, it does a little better, but i suspect it turns the idle speed up a hair, making it easier.

Later, sitting in the grid (before I even had a chance to run it!) the CEL comes on and the cruise light starts flashing. Ruins my day; i head home.

I run the codes and all it gives me is P0031 - Front O2 Heater. Could this be causing all my trouble?

[dentguy05]

I would diag. the O2 sensor problem first. a bad sensor can cause all sorts of issues

[solovus]

Could be...check the fuse.