Car seems to be down on power, where to start looking?

[SoguRacing]

manifold "vacuum" at idle should be 17-21 inches of mercury. yours says pressure so that would be negative 9.8 right? bad intake valves/vacuum leak? your short term fuel trim is rich that's why your short term fuel trim is -5.% you want those to hover around zero. O2 B1,S2: 680-740 mV i think bank 1 sensor 2 is bad. it should read min voltage of <200mv - >800mv but less than 1 volt. your range is way off thus your ecu is getting a mis calibrated signal and making you run rich.

[alkemyst]

Originally Posted by SoguRacing

manifold "vacuum" at idle should be 17-21 inches of mercury. yours says pressure so that would be negative 9.8 right? bad intake valves/vacuum leak? your short term fuel trim is rich that's why your short term fuel trim is -5.% you want those to hover around zero. O2 B1,S2: 680-740 mV i think bank 1 sensor 2 is bad. it should read min voltage of <200mv - >800mv but less than 1 volt. your range is way off thus your ecu is getting a mis calibrated signal and making you run rich.

I didn't check the O2 S2 actively like the S1...I thought the S2 was only used to check if the cat was good and not for any ECU changes.

The OBDII shows Manifold Pressure inHg...it's not shown as a negative number. I checked again and some cars show 9.8inHg at idle would be normal. I will recheck and use my brakes to see if this number changes properly.

If it is a vacuum leak, where do I start looking?