Sy Haw, a 2g logger or a scan tool that will allow you to read basic sensors is all you need.
The front O2 voltage needs to go both fully low and fully high. Harder to read on a cheap scanner as it will not update fast enough but you can get the general idea. If you see min voltages of near 0.1 volt(0.13 etc) and max voltages approaching 1.0, and its steady, you should be fine. Don't worry about the rear one. However I say put it in anyways, and put a cat back in, as there is no way its hindering your performance. Kris R put down 500ish hp at RG with a cat in place. I saw 335 at one time while tuning, and I know that doesn't sound like much, but I am pretty sure its more than you are making.
As for coolant temp, the scanner or logger will read the ECU coolant temp. If it says its -25 and you know its +5 outside, you know its fritzed up. If it says its 7 degrees, but you know the guage on the dash is showing close to full temp, your heater is blowing hot air, and your thermostat housing is too hot to touch, you know its fritzed. The ECU temp sensor needs to follow the actual temp of the coolant. So right now it should start at about 5 deg(ish) and steadily climb to about 105 or so(I am not so good at the higher C temp numbers). If not, its not any good and its a huge part of how the ECU calculates fuelling. Too cold, and the car will be too rich, period, barring a big vacuum leak.
Those compression numbers suggest(along with your eyeballs) a large carbon build up. Do a full MCCC treatment. Get a can of it from the Chrysler dealer, drive the car till its warmed up. Pull the maf sensor plug in and then undo the intercooler pipe at the throttle body elbow. Start the car and try to keep it running. It will stay running in a bit, once it learns that the MAF is unplugged it will try to run on internal backup tables. It may idle poorly but who cares for this.
Keep it running with one hand and spray half the can into the throttle body, revving it a bit to keep it running and not misfiring too badly. When a full half the can remains, let it die or shut it off. The pull the plugs out and spray an equal part down each cylinder, cover the holes with rags and let it sit for at least overnite.
The next day, drain the oil and refill it as the MCCC will have leaked past the rings and contaminated the oil. Get a spray bottle full of water and bring it to the car. Leave the intercooler pipe and maf disconnected. Fire it up. It may be hard to start but get it going, but keep at it. It will smoke fairly bady. When its warm again, spritz the whole bottle of water into the throttle body, keeping it running with your other hand. It will smoke badly again and stink really badly. If it still is really stinky and smoky(not just steam) do anther half bottle.
Put it back togeather, put in new properly gapped NGK BPR7ES plugs, clear the MAF code and drive the car. You should be able to have more boost, more timing, better aircare and better mileage.
