Prius won't shut off at stop lights after fuel injection maintenance

Driving with the selector position in "B" mode is a likely reason for the engine not to turn off at a stop. I would check this first, that the selector is in "D", when driving.

 

I would never use that dealer again. If they coerced you into purchasing a fuel injector service at only 50,000 miles then they are crooks IMO.

One of the most likely reasons for the car to fail to shut off at a stop is extreme heater or AC use or a failing 12v battery. If you were not using the AC heavily then check your 12v battery voltage with no load and after it has sat overnight. If it is below 12.2v then you may have a problem.

 

who is the dealer? i'm collecting names for my 'do not visit' list.

 

A fuel injection service is needed periodically, I would usually do one every 30k. Whether or not I agree with the price they charge though, is a different story.

What was the battery SOC?

 

Fuel injectors are cleaned by the detergents in gasoline. If you need to do it at 50,000 miles something is wrong. If you have to do it at 30,000, something is even more wrong.

Tom

 

The amount of detergents in retail gasoline today are inadequate for long-term cleanliness of the fuel system and combustion chamber. Top-Tier fuels are a bit better in this respect, but are still inadequate for preventing fuel related issues on certain applications, such as the direct-injected designs.

Periodic fuel system cleaning is important to maximize performance. This may include an in-tank additive, throttle body cleaning and a top-end cleaning fed through a vacuum line. However, the benefits in non direct-injected cars such as these, may not be significant.

 

What symptoms should I be watching for? It seems this is something my household should have started paying attention to 540,000 miles (spread across three cars) ago.

 

This is going a bit off-topic but I'm fairly picky compared to most people. Usually the first sign for me is rougher idle and a slight reduction in throttle response.

On the Prius I haven't noticed any significant improvement from fuel system additives. However, on my mom's 2010 Altima V6 I notice a rougher idle and worsened drivability if I do not use a strong dose of fuel system cleaner at least every 5k. Then again, the Altima has a high performance engine (sort of) and is only used for 1-2 mile trips.

 

I'm wondering how long the dealers had the car? Had they run the 12v down by leaving doors open when working on the car? Also, you sure the car wasn't just warming back up causing the engine to run longer than normal? Thirdly, I wonder if they'd reset the cars management computer and it was relearning the parameters. Lastly, are you 100% sure there wasn't a passenger or an item blocking the rear vent on the back seat causing the HV battery to overheat?

Is your car on its original 12v? If it is, you've done well for it to last this long, but I recon the wear it got having the doors open when it was being worked on could have finished it off.

That's all my guesses. Hope you get it sorted.

 

Hmm....

I hope it all works out.

I don't know if I would be comfortable with all that seems to have happened. IMO if you weren't experiencing any peformance issues, I don't think you necessarily needed a fuel injector cleaning. And IMO a fuel injector cleaning shouldn't result in your catalytic converter being toasted, unless they did something wrong.

But on the positve side? Sounds like you get a new catalytic converter.

 

Yet another reason not to let a dealership clean your injectors. If you were out of warranty, you would have been out of luck. The converter being "on its way out" is BS. You'd have to be burning oil or have had some other existing and noticeable problem for that to be a possibility.

 

I'd be curious to know what they use to clean your injectors. Is it an offer the shelf product or do they have their own 'version' which could have contaminated the cat causing it to fail? Especially as they've seen this happen more than once!?! Do they have an old stock of 20 year old cleaner which they're using up? The more cynical part of me would wonder if this was done deliberately to drum up warranty work. Cats will last years and hundreds and hundreds of thousands of miles of hard driving if looked after. I had an old Ford taxi with just shy of 300k miles and was still on its original cat - it rattled a lot but it still worked and passed its emissions.

What has your experience of this dealer been previously? I'm not saying they've done anything wrong, but I'd be interested to hear your experiences previously.

 

Wallet cleaner is more accurate. If you buy E10 regularly, as most of us do, the engine is getting all of the cleaner it needs.

Perhaps the tech left the car in ACC for some time and ran down the battery. In that case it will be back to normal after it has been ON/Ready for an hour.

 

I've heard just enough stories of cats dying shortly after injector cleaning that, absent specific symptoms suggesting such cleaning, I won't allow it on the long-out-of-warranty cars in my household.

 

There's a Minit Lube near us that regularly runs cars out to the front lot, hooks up a bottle of something and runs it through the running engine. If you happen to be walking by while they do this you get thoroughly fumigated by the cloud of rich hydrocarbons blown off. I really think this practice should be stopped.

 

Sounds feasible. I've also found that modern cars will rev their engines when the cat has or is failing. Think it's to do with the management system trying to compensate for the poor emissions readings.

At least you've got a new battery and cat, so all should be well for a while longer now.