P2177 - System too lean off idle - Bank 1.
I am sure this is a very common issue with many cars. But I have not been successful getting rid of this code. I have read many posts related but no luck. will appreciate anyone's input

1. Replaced O2 Sensors
3. cleaned MAF sensor
4. there is no visible leaks - Smoke tested
5. live Data shows everything normal

Anyone had this issue and can suggest what next?

Thanks

 

Is the PCM software up to date? / When was it last updated by Mazda?

 

last year

 

so I have done some more works since. I had a EGR fault code. Cleanned the EGR, metal hose not more codes there Replaced/repaired so far

1. Spark Plugs

2. 02 sensor upstream

3. Purge valve

4. EGR/metal hose – removed cleaned (no code)

5. Intake cleaned

6. Smoke test no leaks

7. Replaced Fuel pump #1 inside tank

8. Removed and cleaned High Pressure fuel Pump

9. Replaced Gas Tank cap

After about a month now there has not been any codes pop up but the 02 sensor, Catalyst and Eval sensor would not reset - Can't get the State inspection done. Very Frustrating.

Yesterday the both P2177 and P2188 (System too lean off idle/at Idle Bank 1) came back. anyone had similar experience? Thanks in advance.

 

Check for vacuum leaks.

These engines are known for carbon build up on the valves. Without removing the intake manifold its virtually impossible to clean them.

 

Thank you. that makes a lot of sense.
How would you clean Valves without taking the head off? Or are you talking about inside the upper plenum?

Thanks

 

Remove the intake manifold and clean out the intake ports. Cylinder head stays in place/untouched.

 

Uh, I see what you are talking about. I did some talking with a shop here they think its the fuel pressure. But we replaced the low pressure pump, serviced the GDI pump and replaced the pressure senson on the rail. there is no codes or indication that fuel pressure has anything to do with. only codes comes back after driving 2-3 weeks is P2177/P2188 and the 3 sensors would not reset.

I will take the INtake out and clean the crap out of that.

 

Cleaned the intake, valves areas, EGR ports had heavy build up. looks like the Evap sensor finally resetted. I still have the Catalyst sensor Incomplete. but new code popped up P2188 System Too Rich at idle - Bank 1.

Oh! this is a never ending pesky battle. anyone had experience this?

thank you again grim_reaper

Smoke tested - no leaks

 

unplug the max airflow sensor