2011 Prius help PLEASE

What test have done that would lead you to think that the fuel pump is not the problem?

Let's look at your data. Long term fuel trim is at +28% at highway cruise/accel- so the ECM is adding a bunch of fuel (aka, a lean condition). But short term trim is close to zero, indicating that right then, the ECM has good fuel control. The B1S1 air fuel sensor is just below 3.3V (slightly rich which matches the lambda figure and mA current). B1S2 is between 700 to 800mV- so I believe what the B1S1 is reporting. MAP shows 3-4" of vacuum when calculated load is over 90%, so I don't immediately distrust the MAF reading.

Now an intake or exhaust restriction could result in the engine performance codes but by itself wouldn't cause a lean code. I would expect most cam timing faults to set some type of cam sensor code. So that pretty much leaves fuel delivery- such as low pressure and volume from the fuel pump or fuel injector problems.

If your fuel pump can maintain pressure at spec under all operating conditions and meet or exceed volume requirements then you won't think or believe that it's good- you will KNOW that it's good.

Posted via the PriusChat mobile app.

 

This might help
p219a Intake Manifold? | PriusChat

 

First off, do you have any misfires? If you have a code scanner that you can monitor misfire counts that would be essential. If you find that you do have a misfire on a particular cylinder, you’ll have to determine if it’s a bad coil. You can do this by swapping the coil with another cylinder that is showing no misfire. If you still have the misfire on the cylinder in question, you have eliminated the coil being the problem and the fuel injector becomes suspect. With the fuel injector being the problem this will cause an imbalance in the air fuel ratio and setting a P219A code.

 

“You can lead a horse to water but……..”

 

.....if you put salt in its oats..... it will drink!

 

Ummm. No where in my previous post did I say "hey you should just replace the pump and see if that helps".

If you want to throw parts at this car then why not replace the injectors? Might as well (could even help with the imbalance code).

That said, ANYTHING that affects how a cylinder functions can trigger that code- compression, valve operation, exhaust manifold leak, fuel injector (or injector wiring), etc.

If fuel trims went from high +20's % to +10% (under all conditions), then yes that's an improvement. No, the downstream oxygen sensor can't cause the imbalance code, and it sounds like normal sensor operation. Sometimes the sensor isn't "turned on" and will read near 0. When driving it is usually about 0.7 - .8V but it will slowly change , anywhere from 0 to 0.9V depending on how you drive.

Good luck

Posted via the PriusChat mobile app.

 

There's a Scotty Kilmer video on YouTube that shows you how to find vacuum leaks.

 

It's not hard, and with your miles? Here's a video, by @NutzAboutBolts:

Attachment has torque values.

 

Great video but cleaning was rather cosmetic (because intake was not really in need of cleaning). These tiny passages were not brushed:



If those clogged then HG goes. So they say. If actual intake channels have dirt so that rag gets dirty it is meaningless unless it’s a race car that need every ounce of power out Even with those beasts porting the manifold to head might be higher in priority

 

A good fuel injector cleaner and chasing down air leaks would be my next move.

My car tripped the lean code and ltft was 20%. It was because I reused the intake manifold gasket when cleaning everything. New gasket solved the issue.

Throwing parts at a high mileage car can be a huge rabbit hole. Chase any leaks properly first.

 

Please keep us posted!