Typically, yes. When the ecu sees a lean mixture from the O2 sensor it will try to compensate by adding more fuel but cant compensate for more than a minor leak. Mostly you will see a lean mixture at ilde then it would correct itself at higher RPM. Thats not the case here From what I can tell from this, the O2 sensor is reading a rich condition and switching properly. Normal readings are typically around .1v Through .9v switching .4v to .8v shows a rich condition along with your LTFT reading of -24 (Rich). I would try swapping the FPR between cars. Edit: Plus having dry carbon/black build up on your spark plugs is an obvious rich condition. If the plugs stay wet and are black then you would have an oil issue. Light brown build up is a lean condition. With a -24 LTFT I wouldn't be surprised if you had black soot coming out of the exhaust at idle. Thats very Rich!
A few minor corrections to that: The LTFT is only -7ish its the STFT (at idle) that's at -24 The O2 sensor drops to 0.04 volts not 0.4 volts But yes there is black soot coming out of the exhaust pipe and I was going to check for fuel in the vacuum line coming the FPR but I couldn't get the vacuum line off of it.
When switching out the O2 sensors, keep in mind that the primary O2 sensors are different between F23 engine types.
That shouldn't be an issue as they both have F23A1 engines, but for some reason they use different oil
Oops I misread that. Seems the O2 is switching but if its duration is significant between high and low voltage it could be a lazy sensor that may just need cleaning. I Dont think that is main the problem though. I'm still leaning toward FPR.
Should be okay. Just make sure to inspect it to be sure its in good condition. You could carefully take it off and re-seat it.
Ok I will try this in the morning, but do you know of any tricks to getting a stuck vacuum line off of the FPR?
I use a pair of needle nose pliers with rubber hoses over the jaws. If it is still not budging and there is some slack in the line you can cut/shorten it. Try to cut the line as close to the FPR nipple as possible then remove the stuck portion after you get it off the car.
