I have a diagnostic trouble codes p1768,po300,and a po420. what does this mean?

That's an enhanced trouble code. To decipher it, we'd need the model year of the vehicle.

Pesky PO420 Codes - Eastern Catalytic

www.easterncatalytic.com/education/tech-tips/pesky-p0420-codes/

One of the most annoying is the persistent PO420 diagnostic code (Catalyst System ... not only shows its teeth when the catalytic converter is on the blink, but can also be ... Most, if not all, catalytic converter failures are caused by a problem or ...

P0420 Error Code: Catalyst System Efficiency Below ...

www.obd-codes.com/p0420

Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency ... If they have failed, it is likely due to something else that caused it to fail. ... the catalytic converter is broken or failed, it may be restricting the exhaust which will ...

explaining trouble codes po420 - po421 - Discount Catalytic ...

Definition of Diagnostic Trouble Code P0300 Category: Powertrain Definition: Random/Multiple Cylinder Misfire Detected

Definition of Diagnostic Trouble Code P0315 Category: Powertrain Definition: Crankshaft Position System Variation Not Learned

Definition of Diagnostic Trouble Code P0339 Category: Powertrain Definition: Crankshaft Position Sensor "A" Circuit Intermittent

po300 is a random misfire code(could be egr passages blocked under upper pleinum;plug wires;plugs or coils.PO420 is catalatic converter below threshold(converter has to be replaced)

your engine is misfiring according to your codes ...4 codes 4 problems
P0300 - Random Cylinder Misfire DetectedP0301 - Cylinder 1 Misfire DetectedP0302 - P0312 Cylinder X Misfire DetectedP0325 - Knock Sensor 1 Circuit (Bank 1)Just showing a few

catalyst system running below threshold. It means you have a catalytic converter problem.

po123-tps curcuit high---po138-02 sensor high volts bank 1 sensor 2,--po205--injector curcuit open cylinder 5,---po305-- misfire cylinder 5,--po300 random/multible mis fire,

Mulitiple cylinder miss fire,May be the coil boots and plugs,will fix your problem,and,or fuel injection cleaner with a couple of bottles of HEET,a water dryer to put in the fuel tank.

P0174 means Fuel Trim too Lean (Bank 2)

P0401 means Exhaust Gas Recirculation Flow Insufficient Detected

P0420 means Catalyst System Efficiency Below Threshold (Bank 1)

Visit http://www.troublecodes.net/OBD2/

and Visit www.repairpal.com

P1768 MEAN TRANSMISSION RELAY ALWAYS OFF..WAS UNABLE TO FIND P1792..IF PROBLEM STARTED AFTER HEADS WERE DONE..LOOK CLOSELY AT AT ENGINE MAIN WIRING CONNECTORS AND GROUND CONNECTIONS THAT ARE ON ENGINE..LOOK FOR GROUND EYELETS NOT SECURED OR LOOSE..LOOK FOR ANY PINCHED WIRING AS WELL..MAKE SURE NO SPREAD TERMINALS IN CONNECTORS AS WELL..YOU CAN ALSO TRY SWAPPING ANOTHER RELAY IN PLACE OF TRANS CONTROL RELAY..MAKE SURE PART NUMBERS MATCH UP..
TCM(NGC)PIN 16 IS TRS T3 SENSE CIRCUIT..PIN 17 IS NOT USED...HAS TO DO WITH TRANS RANGE SENSOR..I DON'T THINK THIS CAUSING YOUR PROBLEM..