986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - STFT spikes of -98.4% causing P1128/P1130 on 2001 Porsche Boxster. Need Help!

paulv · 11-20-2014, 04:35 AM

I would agree with what Topless recommended -- the freeze frame data looks good with respect to fuel trims and the code was set at idle/low load and not at high rpms/high load.

Although it's not obvious, even a pin hole in the exhaust between the engine and upstream O2 sensor will suck in enough air to make the O2 sensor detect more O2 and make the fuel trims go way out in adapting.

Regards,
paul...

11-20-2014, 04:35 AM	#8
paulv Registered User Join Date: Apr 2006 Location: Boston, MA Posts: 221	I would agree with what Topless recommended -- the freeze frame data looks good with respect to fuel trims and the code was set at idle/low load and not at high rpms/high load. Although it's not obvious, even a pin hole in the exhaust between the engine and upstream O2 sensor will suck in enough air to make the O2 sensor detect more O2 and make the fuel trims go way out in adapting. Regards, paul...