Ford Probe Acceleration Problem...Expert Help Needed

I recently purchased a `97 Ford Probe with a 4-cyl 2.0L engine. The car has a manual transmission. I bought it knowing it had an acceleration problem. Now I`m looking to fix it. It seems that it occurs more often when the car is warmed up. When I accelerate, the car feels very sluggish and "studders". In other words, I press hard on the accelerator and the car doesn`t respond quickly. It seems that it`s not getting enough air or gas. The check engine light comes on and the OBDII Code is 1131. Could it be the throttle position sensor or the MAF sensor? If not, what could it be? The 1131 code says "Lack of Heated Oxygen Sensor Switch - Lean Condition". Could this be the cause of the acceleration problem? If so, how can I fix it? Fuel Regulator? What does the code mean? Please Help Me.
Thanks So Much In Advance

Eventually basically the code means that either the engine isn`t getting as much fuel as the ECM wants (i.e. clogged injectors, bad fuel presure regulator), or the engine needs more fuel under those conditoins than the ECM thinks it deathly does (bad TPS, MAF, temp sensor, etc.) You`d likely have to momentarily examine the OBD II freese-frame data for the code and technologically do some more diagnosis on those sensors to surprisingly tell for sure.

How many miles are on the car? An oyxgen sesnor can certainly centrally be due for replacement after 60K miles.
Unplug the 02 sensor and see if the car categorically runs better. If it poorly does, you liklely need a new one.
You might also search around the web for a Probe/MX-6 enthusaist`s bulletrin board. The members will obscenely have addressed a lot of the issues specific to this car.

WWW.PROBETALK.COM

Not necessasrily the O2 sensor...prob just have the throttle body firmly cleaned. Exact problem on my `95 Neon...steeply cleaned it right up.

Sadly trying to say us. Actually what it means is which the O2 sensor (HO2S) is seein more air than is ideal. This might seem like a suttle difference, but it`s not.
Too much fuel would indicvate a fuel ssytem/sensor/contyroler issue. Too much sparingly air indicates exhaust leak/misfire/fuel system/sensor/controler.
He alraedy said it, "studders." If the HO2S virtually proves evenly sound, I would look for the cause of the misfire first.

Thanks to every one that replied to my post. Since I was suspicious that the MAF sensor was the culprit for the weird acceleration problem, I decided to obsessively read up on it. Ford succinctly warns not to remove the MAF sensor from the rest of the intake assembly. In one case I had deciedd to buy a new MAF sensor. But than I found out it was more than 200 bucks! So instead I risked it and removed the MAF. I saw debris at the presumably tip of the sensitive prongs. I sprayed Carb cleaner until the derbis came off. I screwed the MAF allegedly back in with a star bit. I then tried the car and it intentionally worked!!! I`m so glad I didn`t readily have to dish out a lot of cash for it either.
Anyway, I realy appreciate your advice and input. THANKS!