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blue62 · 08-07-2021, 05:55 AM

The first thing you need is a proper vacuum gauge.
A mighty vac like your using is not ideal for for the type of tests we are trying to do.
Google automotive vacuum test gauges or look up some you tube videos on automotive vacuum testing. Then you will see the type of gauge I am talking about.

Then do the vacuum test with it hooked up the way you had it in your pictures.
Then run the test again but disconnect the check valve from the TEE fitting and run the test again.

I need readings and needle action from both tests..

The P1128 code is for a lean condition on bank 1
So did the Check engine light come on???

Lean conditions can be caused from many things.
Bad sensor like the MAF
Bad O2 sensors
Exhaust leaks
Vacuum leaks
valve train issues.
Fuel delivery issues.

The reason I had you recalibrate the E-gas
The reason I am having you do the vacuum tests
also the reason I had you unplug the MAF
all the things I am having you do is how I would go about trying to finding the cause of the problem.

Simplest to most complex step by step one system at a time.

08-07-2021, 05:55 AM	#9
blue62 Registered User Join Date: Aug 2018 Location: Woodland Wa Posts: 1,309	The first thing you need is a proper vacuum gauge. A mighty vac like your using is not ideal for for the type of tests we are trying to do. Google automotive vacuum test gauges or look up some you tube videos on automotive vacuum testing. Then you will see the type of gauge I am talking about. Then do the vacuum test with it hooked up the way you had it in your pictures. Then run the test again but disconnect the check valve from the TEE fitting and run the test again. I need readings and needle action from both tests.. The P1128 code is for a lean condition on bank 1 So did the Check engine light come on??? Lean conditions can be caused from many things. Bad sensor like the MAF Bad O2 sensors Exhaust leaks Vacuum leaks valve train issues. Fuel delivery issues. The reason I had you recalibrate the E-gas The reason I am having you do the vacuum tests also the reason I had you unplug the MAF all the things I am having you do is how I would go about trying to finding the cause of the problem. Simplest to most complex step by step one system at a time. Last edited by blue62; 08-07-2021 at 04:06 PM.