the car is running very bad,i get CE light and run my code reader getting p2197 so I thought I had an exhaust leak.i cant find one, any other ideas...its dropped my mpg considerably...any help is greatly appreciated.

did you seafoam your car it will show your any exhaust leaks

i seafoamed it a while back.I mean could a tiny exhaust leak make my car run terrible..bog down not want to go?

Oxygen sensor locked lean Bank 2

i would look for a vacume leak first you can use starter fluid spray it around vacume line and intake see if you can hear a diffrence in the way the car runs. It could also be your PCV valve. You could also try testing and cleaning your MAF. Or it could be either of your O2 sensors i would start with the heated O2 sensor check wiring.

Here is what I have found on this code.

P2197
Lack of HO2S-21 Switch, Sensor Indicates Lean
Detailed Description
A heated oxygen sensor (HO2S) indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time.
Possible causes :-
Electrical:
# Short to VPWR in the harness or HO2S.
# Water in the harness connector.
# Open/shorted HO2S circuit.
# Corrosion or poor mating terminals and wiring.
# Damaged HO2S.
# Damaged powertrain control module (PCM).
Fuel System:
# Excessive fuel pressure.
# Leaking/contaminated fuel injectors.
# Leaking fuel pressure regulator.
# Low fuel pressure or running out of fuel.
# Vapor recovery system.
Induction System:
# Air leaks after the mass air flow (MAF) sensor.
# Vacuum Leaks.
# PCV system.
# Improperly seated engine oil dipstick.
EGR System:
# Leaking gasket.
# Stuck EGR valve.
# Leaking diaphragm or EVR.
Base Engine:
# Oil overfill.
# Cam Timing.
# Cylinder compression.
# Exhaust leaks before or near the HO2S(s).

^^Those look like pretty good places to start! Can't think of anything to add.

What year, model, and mileage??

How long has it been running badly?

Did the light come on long before it started running badly and the mpg's dropped?

03 light came on right after it started running badly..Maybe a week?two? not long.I will check some of the things listed above and see,what do you mean by heated o2 check wiring?

heated o2 sensor is the second o2 sensor if i recall correctly

but what could be wrong?bad wiring?should i just replace it?

this thread is a waste without year, model, mileage, recent service history in the post

How do you expect people to help... not interested in reading two pages and having to ask for some basic information...

its an 03 as stated above...its one page.......and its a crown vic...hence crownvic.net...its a p71 with 150,xxx.thank you for all the help.

Anybody ever have any luck with this code? My 04 has 150k on it and it throws it when it's cold outside (the light comes on as soon as I start driving away). It did it last Winter but went away once it started getting warmer. Can't say I noticed a huge difference in performance but last night while driving it felt a bit unsure of itself. I've yet to check for vacuum leaks, but what might cause it to only come on when it's cold (50 degrees and below)?

They're all heated O2 sensors these days.