The Prius Experiment

[Blacktree]

It's probably not going to wait to add fuel until the ECU detects boost. That would be too slow, because it takes time for fuel to make its way into the combustion chamber. Chances are, the fueling will be ramped up in anticipation of boost, to make sure the engine doesn't go lean.

Also, I hate to be a dork but maybe this convo belongs in a different thread. We're wandering too far off topic.

[Drifter]

Back in the 80s and 90s we sometimes used water injection with boost to prevent knock. In the 00's people started using water + methanol.

[Blacktree]

The pizza pan video is up! The video includes details on the hardware used for the install, and how I used it, in case anyone is interested. Also included are some tips and tricks to make the project go easier.

https://www.youtube.com/watch?v=iImPsmWtDuQ

[Blacktree]

We have our first fillup since the pizza pan install. And unfortunately, it's a mulligan. Halfway through, the engine threw a couple codes (P0420 and P0172). And fuel economy dropped. The problem turned out to be a faulty MAF sensor. So I replaced it (with a Denso unit). Now everything is back to normal. But we need to "reboot" the pizza pan fuel economy test.

[ps2fixer]

P0172 is a rich code, then P0420 is basically saying the catalytic converter isn't working well. Once the codes are cleared, the P0420 code takes around 30-50 miles to come back if it's still a problem. That's one my car has currently but it doesn't effect much which means the cat on my car isn't plugging up (oil build up most likely would be the cause for that).

MAF makes sense for the P0172 though, it must have been detecting more air going into the ending than it really was getting, so dumped too much fuel. Makes sense why econ dropped and such.

MAF sensors can also be cleaned with a special cleaner sold at parts stores. A dirty MAF can cause similar issues and I'd be checking the air filter and gasket for the air filter cover. MAF's can be really touchy sometimes. Either case replacing it isn't a bad option, big time if they are somewhat cheap.

The car might have to "relearn" how to run again, so the first 10-20 miles it might not run perfectly. Probably not enough of an effect to be a problem with your testing, but it's something to be mindful of. Sounds like it was a sudden change, so I'd guess the MAF went bad.

Hopefully solid increase in the next tank over the last.

[Drifter]

I'm actually impressed by how flush the original wheel covers looked once the car was rolling. It looks like the pizza pans sit a bit proud so I'm curious if they helped or hurt...

[Blacktree]

On another member's 3rd gen Prius they had a measurable mpg gain. Link: https://ecomodder.com/forum/showthre...ted-30234.html

[Drifter]

Originally Posted by Blacktree

On another member's 3rd gen Prius they had a measurable mpg gain. Link: https://ecomodder.com/forum/showthre...ted-30234.html

True, but that was compared to no wheel covers at all. The factory wheel covers are more aerodynamic than bare alloys...

Unfortunately the previous owner threw away the wheel covers on my prius, as do a majority of owners and tire shops...

[Blacktree]

We'll find out soon enough.

[ps2fixer]

Originally Posted by Drifter

True, but that was compared to no wheel covers at all. The factory wheel covers are more aerodynamic than bare alloys...

Unfortunately the previous owner threw away the wheel covers on my prius, as do a majority of owners and tire shops...

Kinda funny, the one I saved from the scrap yard had them (they wrapped straps around the front wheels and messed them up a little). The other 2009 one I have also has them. I heard those are missing all the time, guess I'm just lucky.