Rich-running with minor breathing mods?

[Babalouie]

Hi Steve

Is it pretty normal for a 964 to run awfully rich (as in rich-smelling, and the back of the car being covered in soot after a few weeks of driving) when you've got a few breathing mods?

Say, 100-cell cat, primary bypass and cut airbox?

[Steve]

[Babalouie]

Thanks Steve!

Scantool seems to suggest that the head temp sensor is a-ok. It starts off at ambient temp (ish) on a cold start, then temp readings rise quite quickly, and it maxxes out at 117C when warmed up.

Should I look for vacuum leaks as a next port of call?

[Steve]

OK. Assuming that you have a stock chip in there, I'd be looking for vacuum leaks as well as a bum O2 sensor.

[Babalouie]

Thanks, I've swapped out the O2 sensor for another one I had lying around. We'll see if the bumper still goes black after a few weeks

Will report back