7 Causes of a Toyota P0172 Code: System too Rich - Bank 1
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- Опубликовано: 10 мар 2023
- Causes and fixes for a Toyota with a P0172 engine code: System too Rich - Bank 1
Rich Mixture = Too much fuel, not enough air
Lean Mixture = Too much air, not enough fuel
Possible Causes of Toyota P0172
Dirty Air Filter
Failing Mass Air Flow Sensor
Vacuum Leak
Bad Oxygen Sensor
Thermostat is stuck open
Bad Injector
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Great video thanks
Awesome video thanks
Thanks for the video, it seems oxygen sensors are getting more and more expensive though, an OEM one for my car is like 250 euro these days
Thank for the video
Thanks bro ur the best
Appreciate Cha My Friend!
Excellent video, Thank you.
I have Sienna 2003 .. P0172 and P0174 .. having these two codes at the same time .. Does it indicate something more precisely?
Since the problem is on both banks, it would be something that affects the whole engine, such as a MAF sensor or fuel-related issue.
Quick question, you made a video a while back about fuel pressure and I just wanted to see if you could help. I drive a 2018 Nissan Versa Sv. One day it started to take forever to start and then a month later it died in a parking lot. It wouldn’t start so I changed to fuel pump and it started again but took forever to start again and wouldn’t let me fill up on gas. So I changed the purge valve solenoid (I think that’s the name) and now it fills up on gas but it still really struggles to start. When I do that key test (of turning it on and off again) sometimes it starts back up right away. Do you know what I should do?
I would do a fuel pressure test to see if it is fuel-related and go from there. It should hold pressure, and the correct running PSI can looked up. Auto parts stores will rent out a fuel pressure tester. It is best to first research connecting a pressure gauge to the fuel rail since sometimes an engine will have a connection port, and sometimes they don't.
Injectors leaking down is more likely in a hard starting engine. You can get a P0172 with a low compression cylinder as well. Check fuel pressure drop after the engine stops. You shouldn’t lose more than 10-15% of the pressure that was on the rail at engine turn off.
I have a 2006 lexus is350,check engine light came on for these codes and car would hesitate to get going. I replaced maf sensor cleared the code ,ran good for about 300 miles then the danm code came back on. Guess i need to test some things.
Replace or clean your pcv valve
I replaced both oxygen sensors and just got a new catalytic converter installed on my 09 1.8 Corolla S and I have the P0172 code I’m thinking it might be a vacuum leak, do you think I could try to find it by spraying soapy water around my intake and hoses?
There are several methods I have never tried that one. I always use the smoke machine method. Some mechanics will use starter fluid and spray it at a possible leak location, and if the engine idle changes, they know they found the leak.
@@HVAC_Mechanic gotcha gotcha, the car seems to be showing the green light on my OBD2 scanner, so life is good right now!
@@HVAC_Mechanic thanks again for the info!!!
Hi.. I e checked all those.. the check engine light turned off the it came back on the next day.. it also has a hard start and it still has a slight hesitation on acceleration.. what could it be?
I'd check the loose nut behind the wheel.
Intake manifold gasket
What about an aftermarket Catalytic converter?!?
This is me too. I have an 01 Camry that clearly has an aftermarket kit from engine to exhaust. New cat-converters and all.
is it possible its a bad cylinder 1 coil as well?
It could be a bad coil but usually there will be a misfire code such as P0301.
Toyota don't use O2 sensors, also known as a narrow band type sensor, which are inexpensive to replace, Toyota uses a Air/Fuel ratio sensor, also known as a wide band type sensor, they are much better and are not cheap, they can cost 3x more then an O2 sensor, you can't really clean them up and reuse them 9 times out of 10 they will not work and get worse if you try to clean them and reuse them.
What’s the best way to test them?
There are some ways to test them, but what is the problem that you are having ?
Not good advice. If you had a vacuum leak that would cause an engine lean mixture code instead and not a rich code.. Next thing here is that you didnt mention the usual cause of rich mixture codes which is a purge valve that is stuck closed
In older vehicles, a vacuum leak would often cause a Lean condition; in newer vehicles, the ECU can try to compensate by adjusting the gas/air ratio and often making the mixture richer. A purge valve stuck open may cause an issue when starting, but stuck closed will just give an EVAP code. Always pay attention to other codes.
@@HVAC_Mechanic Youre not a mechanic and everything you stated is pure nonsense. Next, you have no idea who youre talking to here
@@EarlGuyton425
I am not here to argue; I'm just talking about what has worked for me. I've been a mechanic since the 80s; all I can talk about is my own personal experience solving an issue.
@@HVAC_Mechanic MUTED BLOCKED. Youre wasting my time
he's actually maing sense... what's your actual problem... geesh@@EarlGuyton425
Can anyone tell me why my Tundra would only be running too right when I'm in 4 wheel drive low???