Something's wrong. Help!

Okay, this is strange. I started the car to go up to Advance auto Parts and all of the warning lights were gone except the check engine. The car drove normally and I filled it up with gas. The code scan yielded a P3191. Is this the code related to the MAF sensor cleaning?

 

This is primarily related to throttle body interior and throttle plate cleaning, which is not the same as MAF sensor cleaning. However, the relevant TSB also suggests inspecting the MAF sensor for contamination, so it would not hurt to clean the MAF sensor using the correct MAF sensor cleaning fluid.

Note that the TSB (see the link in my post #15 above) recommends applying the throttle body cleaner to a clean cloth, then using the cloth to scrub off the throttle body interior and throttle plate. In other words, refrain from drowning the throttle shaft and intake manifold in throttle body cleaner fluid. Less is more.

 

Thanks for the help. I will clean the TB the first chance I get. also, what is supposed to be used to clean the MAF sensor other than compressed air.

 

This is what I use:
http://www.amazon.com/CRC-05110-Mass-Sensor-Cleaner/dp/B000J19XSA

 

The warning lights are back again. The car still starts normal and runs normally. I have read discussions about the 12V battery and the hybrid battery. Which is most likely to be the problem?

 

Lead Acid 12v. It has shorter life (about half) of NiMH battery. It is easier and cheaper to replace. I would do that first.

 

I went to Advance this morning to have the CEL read and the P3191 code is back. After she read the code and I started the car again all of the warning lights were gone except the CEL. I don't recall if I cleaned the TB before but I sure will do it tonight. Is there anything else I should do?

 

There was another P3191 story a couple threads over, where replacing all four spark plugs was necessary because they became fouled. You might want to check yours. I assume that you know to use MAF sensor cleaner for the MAF and throttle body cleaner for the bore.

 

I cleaned the MAF with MAF cleaner after the first P3191 incident and I also changed the spark plugs. But I did not clean the TB so I will take care of that tonight. Probably put a new air filter in also.

 

Did you ever get your issue solved?

 

The 12V battery powers the main ECU and if the 12V is failing it can cause the ECU to detect non occurring faults. The 12V battery in the Gen 1 Priuses is frail. Since your warning lights go away it may be because the 12V voltage is flucuating. Put a charger on it overnight and see if there is any change to the problem.

 

Problem corrected itself months ago and have had no other issues since.