2003 Ford Explorer with a code P2195

My POS SUV is giving me this code, it is a bank 1 O2 sensor 1 stuck lean. This is the passenger side. Now here are the symptoms:

- When i come to a hard stop the motor will drag down then rev up and chug forward.
- When cruising at any speed (40-75) the car will start chugging, no change in RPM seen, but will keep doing this till i let off and get back on the throttle, almost like it is loading up and then clearing out
- At times i will push the accelerator and the RPMs will rise but lacks power and suddenly i will get power, like a cylinder wasn't firing.
- and this is unrelated but whats the best to check and test door sensors, i just had my door ajar light come on and stay on, and trust me i have checked every door and gate lock pawl and assembly.


So i have done some research and come up with this to check:
- Intake manifold leak
- Broken/damaged vacuum hose
- Bad brake booster (really?)
- Damage to air intake hose
- Exhaust leak

Now if any techs could point me in the right directions and some good methods of testing for the above i would really appreciate it. Another question for the testing aspect, would some starting fluid sprayed around the intake manifold gasket, while running, find my problem or is this just a trick that i should keep to the 2 strokes in the shop?


Thanks,
Matt
You could use the starting fluid but I would recommend something less volatile like carb cleaner. Do this on a cold engine, watch what you spray it on and don't get too crazy with it. No need to make a mini Hiroshima in the garage, and you would look pretty goofy with no eyebrows. As to your confusion about a brake booster being able to cause this, remember that it uses engine vacuum to give power assist to your brakes. If it failed it would leak vacuum as surely as an intake gasket would. Have you tried first just listening to the running engine for the vacuum leak? If bad enough you would be able to hear it.
Got some good advise going on already I'll just add a couple more points....

I'm not sure what tools you have available but if your scanner can give you a data stream & freeze frame data on the code, that would really help you narrow your search..... You want to look the fuel trims... In a nutshell this is what the comp is doing to compensate for a problem. A rule of thumb +20% will set a lean code, -20% will set a rich code.

1st thing would be to test the O2 with propane enrichment to make sure it's working. Add propane and it should go full rich then full lean within 100ms and then start switching.

Look at the freeze frame data and see what the speed was when the code set. If it was idle or low speed then your on the right track with a vacuum leak. If it was at high speed then you are looking at a fuel supply problem, i.e plugged fuel filter, weak pump, etc.

One other quick note if the code is setting in open loop on start up look real careful at the plenum gasket.........