On my 2006 IS350 I recently started getting a P0171 system too lean (Bank 1) code and at the advice of a mechanic I added a techron fuel system cleaner and also cleaned my maf sensor. I've cleared the codes and I do not have a check engine light at this time however the code comes back up as a pending fault but it now includes a P2195 02 Sensor Signal stuck lean bank 1 sensor 1. Any advice on what needs to be replaced?

 

Start by replacing the o2 sensor.

Read more at: https://www.obd-codes.com/p2195

 

Often times oxygen sensor codes are caused by the exhaust leak. Before you start replacing O2 sensors, have your mechanic or muffler shop look under the car to see if the leak in the exhaust is not the issue.

 

Do you think that it would be best to take this to the Lexus dealership? I'm not even sure if I trust the original mechanic I took it to since all he told me was that it would take a ton of time and effort to find out what is causing the original code and that their were no vacuum leaks.

 

Nonsense. Find another mechanic. But definetely dont waste your time with the dealer either. Look through the link I sent you it will be very helpful to diagnose for your case.

 

I too would vote for exhaust leak and / or combination vacuum leak if for example the idle is higher than usual.

Does the power assist from the brakes feel any different? i.e. like it takes more effort to stop the car? Any other work done to it recently?

Likely best to find a new mechanic.

 

Find a mom and pop exhaust shop. Likely, they'll help get your car on the rack and visually inspect the exhaust for damage/cracks for free. The only cost will probably be the welding needed to repair the crack or parts needed.

 

The idle does feel a bit higher than usual and i'm not sure if my brakes feel any different. Vacuum leak does make a bit of sense because when the issue started I went under the hood and moved around a bunch of hoses then the check engine light went away. Will be going to a new mechanic tomorrow likely.

 

Well I took it to another mechanic and they are having a hell of a time figuring out what the issue is. Unfortunately they didn't have enough time to dig into it further due to weather conditions and I'll have to take it back down to then on Monday.

 

Do you have any mods done to your car? Was there any maintenance done on the car recently if so what? Do you have any idea how old the O2 sensors are? Do run 93 octane?
Aathon H.

 

Only mod I have is an F-Sport intake and I got my oil changed a few months ago. Since my car burns oil like hell I top it off roughly every 1000 miles. My rear 02 sensors where changed almost 2 years ago and I do run premium octane. Strange thing is this started happening a day after I pumped gas.

 

I'd recommend in investing in a Bluetooth OBD II adapter, and run it with. Either Fusion, or Torque App. I'd recommend Fusion over Torque though. You can monitor fuel trims, etc ...... With this you can monitor the O2 readings and what not.

For less than $20 you can be diagnosing your own car daily.

Without the headaches that you are dealing with. JM2C

 

I actually do already have a Bluetooth OBD2 adapter that runs torque pro. I only really know the basics of it but I will see if I can get more out of it.

 

Are you the original owner? Do you run the car hard?

 

I am the second owner and i've had the car for about 6 years. Also, I do not drive the car hard.