What Else to do...

Hello everyone, This is my first time posting here, and I want to Thank you all for making this place such a wonderful resource for all things Prius.

Ok, so I recently bought a 2011 Prius with 184k (don’t know which series) however, comes with solar roof and touchscreen etc. I got a pretty sweet deal at an auction and got lucky.( or so do I believe).

The first thing I realized was it had a totally dead 12v battery. And the guy broke the news that it’s been sitting for around 2 years. It started right up and made it home. All 4 tires needed air. The gas probably was 2 years old. Luckily, no check engine or any other lights. It made a 70 mile trip home, with some hiccups here and there.

So, the first thing I did was to order a brand new 12v battery from amazon. Installed it the next day. Drove around for about 50 miles or so and there comes the dreaded triangle which I was expecting ever since I heard the car was sitting for 2 years. Started looking around for all the options within my budget and decided to swap out all the 28 modules instead of just the No.8 which was the culprit. Ordered reconditioned module set with new bus bars. Cleaned up the fan thoroughly and put everything back. The car seemed to be happy. Next, did an Oil and filter change with synthetic 0w20 and oem genuine filter. Swapped out the cabin air filter as well. Did the coolant drain and fill with Zerex. Also, drained and filled the tranny with 4 qt of WS.
Took the car for a test drive and it did make a significant difference untill it rattled at low rpm once pretty bad for a few seconds and later threw a misfire code P0301. Changed all 4 sparks with denso iridium. Even though the old didnt look bad. Next morning got the dreaded morning cold start rattle and knocking. Obviously the plugs had not solved anything so swapped out ignition coil 1 with 2. The misfire code moved to p0302. I was so glad that I had caught the culprit early on, replaced the single coil. The knowcking went away for a couple of days untill it returned with a P0300 p302 p304 random misfiring. So, by now, I had read enough on here about possible causes ( yes i’m ruling out the head gasket at all costs as the more I research the more it signifies a head gasket failure) So, Next, I get down to clean the intake manifold and throttle body thoroughly, it had a pool of oil and gunk. Replaced the manifold gasket and while at the dealership, I bought the PCV valve and replaced it as well. Took out the EGR cooler and valve, it was totally clogged, took a whole day to soak it in few different degreasers and eventually blasted it at the power wash till I could see through every hole inside. The car didnt stop the rattle. Ordered 4 reconditioned denso fuel injectors. The old ones were as bad as it gets. The car behaved for a few days and the rattle came back. The coolant is at the same level and not gone down at all. Also, the coils and plugs were dry as a bone. So, i’m still ruling out the head gasket, even though it’s haunting me subconsciously.

Next, i thought of the stale fuel which i topped off and probably diluted it, so, ran the car untill almost empty and refilled it with premium a couple times. Still no luck, gave it HEET treatment on every refill. Then swapped out the fuel filter inside the gas tank. It made a huge difference. The car runs soo much better.

Have’nt been able to pass smog as the P0A80 is in the permanent code. And everytime I fixed something, I erase the misfire codes which Makes me regret as I’ve read that it will probably go away after approx 600miles. Even though I erased the codes to do the universal drive cycle with no luck. The early morning rattle has reduced by 90%. It has happened once in maybe a week and the intensity of the knock is negligible and very mild. The other day, i noticed some coolant missing ( about an inch less) and my heart sank. I wanted to bang my head against the wall at this point as it confirmed my biggest fear. So, i refilled the tank and it’s been about 8 days and about 300 miles that the coolant has stayed where it was. In all this time the car probably had one or maybe two morning cold shake, its not a rattle anymore, just for a couple or seconds it clanked lightly. The check engine light came on with random misfire and on next start the light went off even though when i scan, the codes are there under confirmed and permanent with p0a80.

i’m waiting to complete that 600 miles to get it smogged. Don’t know what else to do...

Apologies, if the post was unnecessarily long, but I’ve been reading soo much here and learnt everything I mentioned in the post here. That I truly an so grateful to everyone.
Thanks!

(silently gathering up courage to take on the head gasket someday if need be)

 

Yes I totally agree, I was only going the conventional route with the cheapest fix first. I’m glad most of the important maintenance has been done and I did’nt throw any unnecessary parts in.

A quick question that is still not clear, if I clear the codes, does it put me at 0 miles for the 600 miles magic number to get rid of the permanent code P0A080. or it doesn’t matter since it’s stored as permanent and will continue with its tests in the background for 600 miles. Thanks alot for all the replies

 

Thanks for pointing that out. It’s very frustrating that a hybrid battery code would take 600miles to clear itself. (Thats what i’ve been reading it takes to clear itself) i got Dr.Prius app before I replaced the modules. My new assembly’s life went up from 15% to 85%. I’m getting pretty decent gas mileage at 55-56 mpg city/freeway combined.

BTW, forgot to mention that the car had a recall for airbag and software update. The dealer offered to look into deleting the hv battery code, since it’s causing smog to failure. Came back with suggesting that I need to replace the HV battery with a quote. Also, told me that permanent code cannot be erased.

 

Battery health before and after by Dr.Prius