I had a code P0121. I bought the sensor and had it replaced, now the code still won't clear. I need an inspection ASAP but the check engine light is still on.

p0102 is MAF mass air flow , circuit low input. Try these to reset code by trying following.
Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires. Inspect for any air leaks near the MAF sensor. Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor. Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information) Replace the MAF sensor.
P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem
P0108 EGR Barometric Pressure Sensor Input Signal is out of self test Range. P0300 Random Misfire Detected.

As for your codes p1131 and 1151: Ford - Lack Of Heated Oxygen Sensor Bank 1 Sensor 1 Switches - Sensor Indicates Lean


Last week I had the very same catalyst, evap and ECG codes come up on my 1999 Mercury Mystique which is like a Ford Taurus. A friend was able to find a hole or leak in the hose connected, replaced it and it runs fine. I havent run it a full and straight 50 miles yet to clear the check engine light but that repair alone changed the entire way the car was poorly driving. Im sure that hasnt fixed all the probs but thats a good starting point.

P0121 - Throttle Position Sensor/Switch A Circuit Range/Performance Problem

The Throttle position sensor is a potentiometer that measures the amount of throttle opening. As the throttle is opened, the reading (measured in volts) goes up. The powertrain control module (PCM) supplies a 5 Volt reference signal to the throttle position sensor (TPS) and usually a ground also. A general measurement is: at idle = .5 Volts; full throttle = 4.5 Volts. If the PCM detects that the throttle angle is greater or less than it should be for a specific RPM, it will set this code.

Potential Symptoms: Symptoms of a P0121 trouble code could include:
Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light)
Intermittent stumble on acceleration or deceleration
Blows black smoke on acceleration
No start

Causes: A code P0121 may mean that one or more of the following has happened:
TPS has intermittent open or short internally
Harness is rubbing and causing an open or short in the wiring
Bad connection at the TPS
Bad PCM (less likely)
Water or corrosion in connector or sensor

Possible Solutions:
1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they're close to the specifications mentioned above. If not, then replace the TPS and re-check.
2. Check for an intermittent open or short in the TPS signal. To do that, you can't use a scan tool. You'll need an oscilliscope. The reason is because scan tools take samplings of many different readings over just one or two data lines and can miss an intermittent drop out. Hook up your oscilliscope and watch the signal. It should sweep up and down smoothly with no drop outs or spikes.
3. If no problems were noticed, perform a wiggle test. Do this by wiggling the connector and harness while watching the pattern. Does it drop out? If so, replace TPS and re-check.
4. If you have no TPS signal, check for 5 Volt reference at the connector. If it's present, check the ground circuit for open or shorts.
5. Make sure the signal circuit isn't 12V. It should never have battery voltage. If it does, trace circuit for short to voltage and repair.
6. Look for any water in the connector and replace TPS as necessary.

Other TPS sensor and circuit related DTCs: P0120, P0122, P0123, P0124

see what the code is and have it fixed

If the car is pinging you will set a knock sensor code.'
This comes from bad gas and running lean., You really need this professionally inspected to rule out the basics. I have seen alot of nissans with the knock sensor code stored but the light is still off.
Fill up the tank with high octane chevron and some techron injector cleaner and clear the light. If it stays off for a couple days then go get it inspected. Even if the code is stored it will still pass as long as the light is still off and the monitors have run.

after you change the TPS sensor you need to clear the code from the computer to make the light go out

A code P0121 may mean that one or more of the following has happened:

• TPS has intermittent open or short internally
• Harness is rubbing and causing an open or short in the wiring
• Bad connection at the TPS
• Bad PCM (less likely)
• Water or corrosion in connector or sensor

(TPS = throttle position sensor - mounted on side of throttle body and connected to accelerator linkage.)
Causes A code P0171 may mean that one or more of the following has happened:

• The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
• There could be a vacuum leak downstream of the MAF sensor.

Possible Solutions Possible solutions include:

• In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
• Inspect all vacuum and PCV hoses, replace if necessary
• Check for a dirty fuel filter and proper fuel pressure

Hope this helps.

I believe all the Mopar OBDC codes are the same. A list of the 2001 codes were posted on a PT Cruiser site here: 2001 Chrysler codes

Your error says the throttle position sensor and MAP sensor disagree with each other

did you check voltage to sensors if you need help with proedure, contact me, or you may try patrs houses on line in how to section.