bank 1 bank 2 lean BUT...

[short_mom629]

My CEL is on AGAIN, showing codes for banks 1 & 2 lean. However, I have replaced the IAC valve, the MAF sensor, all plugs, all 4 O2 sensors, AND had her smoke tested TWICE for a vacuum leak - she's tight as a drum. I am pulling my hair out here!! Still expiriencing a jumpy idle while in gear at idle; bounces between 400-700 RPM when I am at a red light, stop sign, dropping off my kid at school, you get the idea. Any ideas to toss my way?

Oh, I also ran some Lucas fuel injector cleaner in my last tank of gas. I'm stymied, guys... Help a mom out here?

Thanks!

 

[Yudaman]

Thinking outside the box, when is the last time you changed fuel filters?
If the filter is plugged that would limit fuel to the engine making a possible lean condition.

Just a crazy thought...

 

[bedrck46]

I would suspect the throttle body needs the exhaust ports cleaned out also could be a problem with the DPFE Sensor

 

[short_mom629]

Wouldn't that give me problems while accelerating and driving, though? I am only having issues while idling in gear.

 

[bedrck46]

Checking your past post from January you stated what you have had done to the expy within the last 3 months Its now almost a month and a half later. Things may have changed in those past months. Take and spray some Carb Cleaner around the vacuum hoses, throttle body and in the area of the DPFE and see if there is any change in the RPM's if so you may have developed a vacuum leak sing the previous work was done.

 

[Goats]

I would suspect the throttle body needs the exhaust ports cleaned out also could be a problem with the DPFE Sensor

Most of the time the dpfe sensor would throw a egr code

 

[bedrck46]

Most of the time the dpfe sensor would throw a egr code

Agree but worth checking also key words here are "Most of the time" which I would take to mean Not all the time

 

[bedrck46]

P0171 - System to Lean (Bank 1)
P0174 - System to Lean (Bank 2)

For lean and rich DTCs:
Fuel system
Excessive fuel pressure.
Leaking/contaminated fuel injectors.
Leaking fuel pressure regulator.
Low fuel pressure or running out of fuel.
Vapor recovery system.
Induction system:
Air leaks after the MAF.
Vacuum Leaks.
PCV system.
Improperly seated engine oil dipstick.
EGR system:
Leaking gasket.
Stuck EGR valve.
Leaking diaphragm or EVR.
Base Engine:
Oil overfill.
Cam timing.
Cylinder compression.
Exhaust leaks before or near the HO2Ss.

 

[Jracerinfl]

Most certainly a vacuum leak. Most common are the PCV connectors and elbows. Check every line/hose after the mass air sensor.


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