Sluggish Acceleration/Bad gas Mileage

Need to get a competent mechanic to run a scan and check for head gasket seepage or leakage known issue for these motors be prepared

 

I would suspect battery may be overheating and not giving you much assistance, check the battery fan is clean.. It is an easy DIY and it doesn't take much to clog up and affect cooling.

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You'll need the plugs before long, but you might still have 6 months. Do not buy online, Amazon and eBay are swamped with counterfeits.

The EGR has no direct impact on MPG or acceleration. I won't say it is unimportant, but it doesn't urgently bear on this situation.

Transmission fluid: forget about it, won't help a bit. Maybe do it in the spring if you're bored and have extra cash then.

Check/clean battery fan: do this right away yourself, youtube shows you everything. If you don't own a vacuum, head down to the DIY carwash place with a roll of quarters and a screwdriver to help with the panels and ducts.

 

I agree. Just get them from the dealership. They are even usually cheaper there than the denso ones at the local parts store.

I might disagree on this one, but I'm not going to be definite on that. If the egr is clogged, then it probably would hurt MPGs, especially if there oil in the intake manifold and all the ports are clogged. That's how mine was. @Mendel Leisk might provide some more insight on the EGR.

Transmission fluid exchange on mine helped the car accelerate smoother. Probably not helping with MPGs, but it is a good maintenance item. It was only $149 at the dealership. I didn't want to mess around with that one.

YES, YES, YES! Very important. You don't want to ruin your Hybrid Battery.

 

That would be good to do too.

 

Clogged EGR runners in the intake can definitely effect MPG and performance, but I don't know if it would be described as sluggish as much as rough running. Does high RPM's help at all? If not, then it's probably not that.

If the plugs are original I highly doubt that's it, those Denso iridium's can last for 200k+ easy. Not to say they aren't worth checking, especially if the car was bought used, or if they have been changed.

I would absolutely monitor the battery temps and see if you can tell any performance differences when it's hot or cool. if you get the Hybrid Assistant app you can set your fan to high speed and see if it helps get temps down (mine barely helps). My battery gets to 125F easy without any performance issues. When I've seen it really high I do feel like the car is a little sluggish. I doubt a clean fan will help much, but I'd still get it done if you think batt temp is the issue. Also, make sure you are running the A/C as much as possible.

 

Heavy AC use? Any extended idling in parking lot with AC?

In addition to tips above: cleaning throttle body might help. Probably in conjunction with EGR/intake manifold cleaning.

 

Well , your location indicates a hot location , my advice ,use AC for your confort , if you are good in the car , then the battery is happy

 

I agree with @Louis19 above. "full blast" may or may not be necessary, but generally if the driver is comfortable then the battery is also being cooled adequately.... assuming that the cooling fan is working and ductwork isn't full of dog hair.

 

I replaced my original plugs at 216k mi. on my 2012. They were still fine.

 

I don't know that you even need to remove it. The primary tool for cleaning one is a powerful vacuum cleaner, and maybe a reach attachment for it.

Our car is the c model which has a different set of ductwork... the only other tool we need for ours is a flat screwdriver for dealing with the plastic popper fasteners. I couldn't say if your liftback model is much different; never did one of those.

 

This is the video I used. I took out the three small screws that hold the two pieces of the fan together and alternated between two cans of air. It made it much easier to clean. Just take your time with it, and don’t forget to shop for one of those clip on filters. I also would recommend you get Dr Prius app and one of their recommended Bluetooth obd to get a better idea on what’s going on with the hv battery.

 

How dirty was it?

 

For the Hybrid Battery Fan Filter