Po128 po131 po300 po463 - 2000 Buick LeSabre

The codes p0452 and p0463 refer to the fuel sender unit. There may be a wiring problem and the gauge is not working properly.
p0128 indicates that the engine is running too cold. Possible stuck thermostat in open position. This would cause the engine to run a richer fuel mixture.

Those are zeros, not Os - P0128, etc. Put your car year and model with the code into Google. You'll get all the information you need.

po106 MAP/BARO sensor range preformance po128 thermostat range is below regulated temp po300 random engine misfire po606 PCM internal preformance error. some one has chipped there engine.

all the codes you have listed are concerning the exhaust/emissions and random misfire , check all air intake hoses for leaks/wear etc ,check condition of spark plugs renew if in doubt ,take it from there

the po300 are multiple miss fire the others are related to the o2 sensors

Thermostat failure, random misfires detected, idle control errors. Severe vehicle overheat condition could set po300 and po506. Recommend replace tstat and seal , clear codes and recheck.

For PO300 you need to change out the Fuel Leveling sensor and/or the fuel pump which are one in the same. If you do so,you will have your good old peppy - responsive and well tuned truck back! I've got an `02 of the same truck 5.3lit. That fixed me rite up!!! My codes were PO300 &PO463. Runs like it's NEW again! Really hope this helps!!!!!

CODE O141 IS AN O2 SENSOR WHICH IS NOT WORKING
CODE P0300 IS A RANDOM MULTIPLE MISFIRE WHICH IS IN RELATION TO THE FIRST CODE
CODE PO455 IS THE EVAP PURGE CONTROL VALVE WHICH IS SHORTED (NOT WORKING)

code p0335

replace your bank 1 (driver's side) position 1 (pre-convertor) O2 sensor. It probably will be completely black, the p0134, 134 and 1133 are all for that O2 sensor, the P0171 is for lean fuel trim on bank 1, and the p0300 is for a misfire probably caused by the lean fuel mixture.