What dose po172 mean

What make and model car ? P0172 OBD II Trouble Code could be running so rich that it fouled the sparks . Pull out the spark plugs and see if there are wet with fuel and black, means that they are fouled out. Have to be cleaned or replaced . I don't know the make of vehicle , so I can only give approximation what mite have caused this , a fuel pressure regulator with a ruptured diaphragm leaking fuel into the intake manifold, leaking fuel injectors P0172 System Too Rich Bank 1

Code 172 means the fuel mix is too rich on bank one. If you have a 6 cyl engine there is only one bank of cylinders. The problem could be the O2 sensor or a leaking injector among other things.

Po172 refers to an oxygen sensor. But after you service the part you need to clear the code with an OBD II scanner. You can get a reliable inexpensive one at Harbor Freight. After you clear the code then you to start the car and drive it to see if the code comes back on. Also if you have a vacuum leak this can cause the system to run either rich or lean depending on circumstances.

code po172 refers to system too rich, bank 1===causes ---intake blocked---EVAP canister purge valve---fuel pressure---EGR system---injectors---HO2s

abs light on means some fault codes stored in your car,
toyota it2 can help you clear the code and turn off the light with airbag.

did you check your o2 sensor fuses?

Think your guy changed O2 Sensors ,
but didn't consider that your sensors PO172
is rich,because it is correcting for a lean condition


I'am going to really guess here

The EVAP has leaks,but no codes set,
partially driving the system lean (Vacuum Leaks)

The Converter is sort of out there as
not working well either

I would smoke the EVAP System and everything else,
intake manifold etc

I think you will find this by MAYBE even just looking
for a bad hose leak

Is that data from your mechanics scanner ?
What is their theory ?

Bank 1 has a vacuum leak I think !! ??

have coil packs checked,possibly incorrect length spark plug wires,will cause miss fire also

Whats going on here is that you have a too rich fuel air mixture. This will cause your misfiring and set off the PO172 Code. Your Bank 1 O2 Sensor is picking up the too rich mixture. This O2 sensor is location on the #1 Cylinder side (so you problem could be in #1/#3/#5 Cylinder). A dirty MAF Sensor, loose plug wire, dirty/broken spark plug, dirty fuel injectors, vacuum leak, and PCV Valve could all be a cause. I would run some injector cleaner through and also clean the MAF Sensor, change your PCV Valve. This would be an easy and cheap start for you. Good luck and thanks for using FixYa!

Sincerely,
JC

have u checked/ replaced your o2 sensors since you have owned the vehicle?