Changed PCV now Misfires and ICE Won't Start, please help!

Hi All,

I have probably spent about 8-10 hours scouring Priuschat for an answer but am just getting more confused. I am really at my wits end and hope someone can help get my car back up and running.

As an introduction I have a 2001 prius with about 230k miles on it.

For a couple months, I've been getting the P0171 error code.

2 weeks ago I cleaned the MAF with MAF cleaner and scrubbed the TB with carb cleaner, put everything back together, cleared the code and no problem. I also got an oil change around the same time.

1 week ago, the P0171 code came on again.

2 days ago I replaced the MAF and the PCV valve. While replacing the PCV valve I unplugged the coils and fuel injector plugs so i could move the piece that the wire harnesses attach to around. The harness did not move much but I was able to get access to the pcv valve and replaced it.

After putting everything back together, I turned on the car, it would run for about 5-8 seconds and then start shaking real bad, and turn off and give me a solid big yellow triangle.

I went back and put the old PCV valve in (I could shake it and it sounded the same as the pcv valve, i was also able to blow air through it from both sides fine, did not seem seized) and the old MAF sensor in and it did not solve the problem.

I am able to turn the car on, within the first few seconds, put the car in neutral and the car just keeps shaking really badly. After leaving the car to shake for a few minutes, it throws a P0300, P0303 and P0304 code.

When I leave the car in neutral, it shakes really bad and THERE IS NO THROTTLE RESPONSE. Car works fine when i put it in reverse. When i put it into drive, THERE IS NO THROTTLE RESPONSE.

The P03XX codes made me think it was a spark plug or coil issue, but after doing my research, I saw a few posts where Patrick Wong say that if there is no throttle response in neutral, then i should just have my car towed to the dealership.

Is there a chance my issue is caused by a bad spark plug and coil? Is there anyway I can rule out the possibility that I pinched one of the coil plug wires or injector wires while I was trying to replace the PCV

Any help would be greatly appreciated.

Thanks!

Edit: When I was replacing the PCV valve, my gas gauge was blinking. I put about 3 gallons of gas into the car, so it is at 3 bars of fuel currently. Not sure if this makes any difference.

 

Thanks, I ordered new plugs, 2 new coils, new MAF, will start testing this weekend and report back!

 

Ok, new data points.

I replaced the plugs this morning and have uploaded the 4 plugs in order from bank 1 - 4. I have also uploaded a closeup of plug 4 and plug 3. Plug 4 was completely black which doesnt look good. Does this signify an oil leak? These plugs have been in the car about 2 years, probably 10k miles.

When I turn the car on, it just shakes really bad, it doesnt die on me anymore.

I switched coils 3 and 4 with 1 and 2.

I cleared the codes and now have code P0303, which is weird because I wouldve thought from the pictures bank 4 was my problem.

I also hooked up a multimeter to the adapter that plugs into the coil and can confirm I am getting about 13.5V on plug 3 and plug 4 so it seems like current is traveling through.

I tried to get a multimeter reading from the plugs that go into the fuel injectors but they all just say 0.

I also tried putting a long screw driver and touching the injector but couldnt really hear anything. The car is shaking too hard the engine noise is just way too loud.

As a long shot I also disconnected my battery for 20+ minutes and then plugged it back in which didnt seem to help.

Thoughts? Thanks for helping everyone!

 

I’m pretty sure it’s not pcv. I put the new pcv on and that’s when the problems started, then I inspected the old one which sounded like it was still working so I put the old one back and it didn’t fix the problem.

I can put the new one back on if you think it’s worth a shot.

I was hoping the community could help read the plug. I noticed the staining but because it was near the porcelain section I didn’t think it was a big deal.

 

Do you think the injectors are the most likely culprit now?

 

Hi all, sorry for the delay, I was out of town for the past few weekends and waiting for an in line test kit that I ordered. I will try and cover what I've tried so far.

New information - I had to move my car for street sweeping and although the car does not stall out after I turn it on, it shakes really badly. When you press the throttle down fully, the car will limp forward extremely slowly (slower than it takes to walk). I had my wife press down the the throttle while I pushed the car from the back and I noticed a lot of white smoke coming out of the tailpipe, this was never an issue before. I couldn't identify the smell but it did not smell good (a little bit sulfur-ie).

I can turn the throttle body pretty easily when the car is off. After turning the car on, I can still turn the throttle body but it becomes much more difficult to turn, however I am still able to turn and open the throttle body but it'll hurt your hands to do so. I can also confirm that when I turn the throttle body with the car on, I do not hear any change in the revs (I am not sure how hybrid motors work).

I haven't gotten an injector cleaner but the in-line test kit (in-line spark plug and fuel injector plug tester) showed that all 4 coils are working fine, the spark plugs are new so they shouldn't be an issue. I have also tested the fuel injector plugs and they are working fine per the in-line test kit. I have also hooked a multimeter to the fuel injectors themselves to see the resistance and they are all showing 12.7 I believe.

I will try this next, how long will I need to keep the car on for?

My understanding so far is that we can rule out spark. Fuel and air have not been ruled out. The fact that this all happened right after I changed the pcv valve makes me think I may have botched something while doing so but looking at my engine I simply cant figure out what I could have broken. I tried both a new pcv valve and old valve, the only things I moved while replacing the pcv valve were the wire harnesses and the in-line test kit should have confirmed that the harnesses are still fine. The hose that connects to the PCV valve seems fine. Is it possible I somehow damaged the internals of the hose while plugging it back in?

The PCV valve would account for air being the culprit, and the only culprit left for fuel seems to be clogged injectors. I just don't see how my injectors could have become clogged while changing the PCV valve.

Is the next best step to try fuel injector cleaner, and if that doesnt work, remove the injectors to take a look? That starts becoming something that may be above my abilities, but I am willing to try.

Sorry again for the delay all, I definitely am not trying to just glean advice from you all without updating everyone on solutions so there is a reference for future members.

Thanks again for all the help, definitely very appreciated!

 

I replaced all 4 plugs, #3 seemed fine apart from the discoloration on the porcelain.

I am really hoping it isnt a blown head gasket or cracked head as those pretty much spell game over for the car.

I have never had an overheating event, at least not to my knowledge.

Yea, depending on what everyone recommends it seems like there's a chance I'll be letting the car go, kinda sad this all happened as a result of maintenance.