Just started the Gen 2 after about a week of sitting idle. Had both coolant circuits changed out a few weeks ago. Dr. Prius shows 0300, 0302, 0303 and 0304. Spark plugs changed about 40,000 miles ago. Coolant levels are normal. Possible all coils are bad? I always fill up with top tier Sunoco, but the last fill up was at a convenient store, because it was convenient. Could it just be crappy gas causing this issue? I’m stymied…any ideas would be most helpful! Thanks in advance!
To build a bit on Bisco's comment, and always seeking the lazy way out -- if you have no issues other than the lights, I would clear them and see if they come back.
One more random quibble: when posting about trouble codes, please include the letter (P, C, B, or U) that starts the code; it's part of the code. We know you meant P0300, P0302, P0303, P0304 in this case, but there are a lot of codes that aren't as familiar to everybody as those are. Diagnosing misfires can be a challenge. There was a pretty good article on it in the Second Quarter 2009 issue of Toyota Tech (starting on page 15). My only misgiving on mentioning it here is that it was specifically on how some of the ECU features for supporting the diagnosis changed for Gen 3, so it probably doesn't map seamlessly onto your Gen 2. But it's still a good source of general ideas and ways to look for information that can help.
Noticed when first started, a little shaking. Dissipated a bit as it warmed up, but not entirely. In speaking to my wife she reminded me that this happened about a year ago when buying gas at a discount station. The only difference now as compared to then is that this time it threw multiple P0300 codes, where as before it was just a single cylinder code. Just drove it then until about half empty and filled up with top tier fuel. Problem went away. I guess that’s what I’ll do and hope,this is actually the issue.
About 180,000 miles now. Gen 2…all burn oil, some more than others…About a year ago, based on recommendations from other PriusChat members I did a few things that has minimized the oil burning problem. Did the BG products 3 part system and changed to a full synthetic 5/30 oil.