Check hybrid system warning, prelim diagnosis

1/14, the check hybrid system stop vehicle in a safe place warning came on in my 2012 prius 3. i was able to drive 4 miles home at 30mph with no issues. car has 162k miles, bought new, always serviced at dealer, no major repairs (just brakes/filters). I have been driving it 2-300 miles/month since 9/22, and it's been parked in the heavy rains we've been having (no flooding). today it was sunny out. so i went to run basic diagnostics with Dr Prius and came up with the attached readings. not sure how to decipher. the car will start and drive, but in limp mode. also, sometimes the engine will run, other times it won't kick on. i noticed when i stopped the engine it went to bed with a rattle sound (I didn't try to repeat it). the car has original plugs (was about to change in the next few weeks). i am thinking it might be the plugs, EGR (the rattle), maybe the HV battery (and/or fan), or the 12v battery. I haven't disconnected 12v yet, as I don't want to clear the codes. suggestions/recommendations would be most welcome. I called a mobile mechanic to come out and run the full diagnostic check for $150. i'd like to keep her...she's been good to me, she drives well, and she isn't encumbered with a loan.

 

Update: Appreciate the replies. I went ahead and changed the plugs myself. Took all of 30mins, not bad at all. Started the Prius, warning light came on, but then the ICE cut out (seemingly going into hybrid mode). I turned off the car. I started it again. The engine turned on, and after letting it run for a good 4mins, I turned it off and the rattle occurred (incidentally, it was never a start-up rattle, but rather a brief 1-2 second rattle upon turning off engine). Anyway, I took one poster's snarky comments re the $20 OBD scanner. I got one from Amazon, it spit out no codes. I had another delivered a few days later, tried the same drill, but again, no codes. Oddly, after trying the second scanner, I turned the car back on and the warning msg was gone. I drove the car around the block, maybe 1.5 miles, thinking all was well in the world, but the "check hybrid system/stop" warning reared its head again. The 12V battery reads 12.3V (changed it in 2015, so it's almost 8 years old?). My next course of action will be to check the hybrid fan. I noticed I didn't hear the fan turn on the last 2x I started engine after plug swap (and during the short drive). Can a bad EGR bring up the particular warning message I'm getting? Additional ideas/thoughts are welcome, before I bite the bullet and take it to a local mechanic for a deeper (and hopefully, final) prognosis. Thanks. JR

 

Excellent tip, thanks...will inspect/clean that pipe this weekend.

 

Update: car has been sitting for a week, no starts; this is 2 weeks since plugs were changed. Yesterday, I started it, smooth engine, and just the check engine light turned on, no Check Hybrid Status. I let car do its usual cycle into hybrid, let it run for 3 mins, then rolled it into the driveway to dismantle/check/clean the hybrid cooling fan. That went well, the fan showed no great dust build-up. Reassembled fan. Then I plugged in a new OBD scanner, and <drum roll> this one pulled up codes. I assumed these were from before I swapped the plugs out: it was cylinder misfire x 4. I cleared those codes, and the check engine light also went by the wayside. I test drove the car around the block 2-3 times, and the engine had noticeable pep, like when she was new. I parked it and let it run another 3 minutes, no sign of the spooky warning OR the engine rattle when I turned the engine off. I am still going to clean EGR pipe. So, for this repair session total outlay thus far: iridium plugs ($55), OBD scanner ($25), new DeWalt impact drill and bit set ($125). Will update.

 

Additional post-spark plug change update (3/5/2023). I currently drive the car 2x a week (it's a third car). I most recently logged 30 miles driving around town. The acceleration in Power mode seems to be back, courtesy I assume of the new plugs. Warning lights haven't come back since the plug change and my using an OBD scanner to clear the cylinder mis-fire codes. I want to thank you all for the advice, especially the bloke who suggested I buy a $25 OBD scanner rather than pay a mechanic $150 to do the scan for me! Ciao. JR