p3191 01 prius enigne shuts off

Some owners use a can of throttle body cleaner; just spray it in according to directions.

I remove the air cleaner assembly for easy access. I've used Q-tips with rubbing alcohol to clean off the throttle body and throttle plate. I have also used just a paper towel moistened in water to wipe off the deposits. They come off very easily.

Are your spark plugs in good shape, your oil viscosity 5W-30, and oil level not overfilled?

 

I have had it happen twice over 8 years in the '01. So far it seems to be the convergence of a hot day, and really transitioning fast from starting to putting the car in reverse. Ensure that the air filter is really clean.

 

OK, then you might like using either of my two cleaning methods described above (Q-tips or a damp paper towel), since no fluid will enter the intake manifold.

However this requires you to remove the air cleaner housing from the engine. Two bolts attach the housing to the valve cover. Two hose clamps and the wire harness for the mass air flow meter have to be removed.

 

You can rotate the spring-loaded throttle shaft by hand 90 degrees, when the car is IG-OFF. Clean the throttle body interior and both sides of the throttle plate. When you see only shiny metal and no black gunk, you are done.

 

You should use Mass Airflow Sensor Cleaner for your MAF and Air Intake and Throttle Body cleaner for the rest. CRC makes both. Their MAF Cleaner is safe on sensors with plastic housings. Don't use cleaner or carb spray.

 

Try to remove the MAF compartment and the throttle, clean them up with mass air flow cleaner (from AutoZone) and clean the throttle with throttle cleaner graded for vehicles with O2 sensors and Catalytic convertors (which is typica throttle cleaner). I just did this today after receiving an error code P3191 and my 01 prius is back on the go.

Let us know if it works. If it doesn't, then you might have a problem with your fuel pump.

 

This might help:
Cleaning Prius Throttle

Bob Wilson

 

good tutorial bob! should apply to nhw20 priuses as well.

 

I suggest taking care of the cylinder misfire problem before you continue to work on P3191. Is the cylinder misfire limited to one cylinder or is it a general P0300?

How long has it been since the iridium spark plugs were replaced? If they are not relatively new, why not replace them now and rule out that particular issue. Also inspect the spark igniters while they are out to make sure they are in good condition (the plastic body is in good condition, no water in the spark plug wells, corrosion, etc.)

Can you measure fuel line pressure? That would demonstrate whether the fuel pump is OK or not.

Have you seen TSB EG011-03? If not I have attached it for your info. This provides info on acceptable fuel line pressure.

After you've ruled out or corrected all other possible issues - if the car still has a P3191 problem, then you might want to see if you can buy a salvage engine ECU of the correct part number: 89661-47054.

 

I have had the same problem, but not as many times. I do notice that the misfire codes seem to come with the P3191 codes just due to the engine stalling. One thing to pay attention to - how long is the time between engine start and putting it into gear? The couple of times it has happened to me, I almost immediately went from start to reverse, followed very quicklly by the engine lugging, and then stalling with a good shake. Yet immediately after turning off and restarting, no sign of the problem (other than all the warning now locked in).