Hybrid system disrupted after dealer service?

jaycassano · Nov 4, 2024

Hey RAV4 users,

I recently had my car (2019 RAV4 hybrid, ~40K miles) serviced in a dealer. Dealer "recommended" a bunch of services, including A/C evaporator cleaning (with some expansive foam), and fuel system cleaning, in addition to other things like oil change, tire rotations.

My car was in perfect condition. However, after the service, the car feels noticeably less powerful than before (It has been more than 1 month now). Check engine light was triggered during that service. Two codes: (P0171) bank 1 system too lean; and P3190 poor engine performance; poor engine power. Dealer claimed this was not unusual when doing the fuel system cleaning because they disconnected things, etc. Anyway, no active codes right now.

However, the car just felt very sluggish when accelerating. I feel it struggles after 20mph onwards. I had to push gas more and the engine makes more noise, revs more, yet it produces less power than before. I went back to the dealer, and they "checked everything" and concluded nothing was wrong. They claimed fuel pressure was fine.

I am still not convinced. On the road, the car just falls behind lower end cars (say when traffic light turns green and every car accelerates). Recently, I started to turn my attention to the hybrid charging/output pattern. I notice the following: 1) the battery likes to charge more (from wheels, or from engine); 2) when the battery outputs power, the battery level drops slower than before -- this seems to suggest that the battery to power generation is less efficient; 3) as a result, the battery tends to maintain at a higher level (e.g. 80%+ full); before it usually hovers around 50~60%.

One more thing: the mpg dropped about 3 points from 38mpg to 35mpg.

I wonder if it's possible the service disturbed the hybrid system in some subtle way? One explanation of the less power is that the electric engine is "lazier" now. Is it possible the stupid A/C evaporator service's expansive foam went randomly into other components and disrupted electronics? The fuel system service itself is a strong suspect too.

What can I do? I have an OBD2 scanner (w/ an app) that can check metrics like long term fuel trim, etc, but data for the hybrid system seems scarce. Any data I should watch out for? The app can record the metrics.

Is it worth going to another dealer and pay some money for a diagnostic? The dealer claimed my car passed all the health checks and I should stop worrying.

Any inputs will be appreciated. Thanks!

Jay

Exfordman · Nov 4, 2024

I have seen false lean codes after a fuel injection flush. I have seen MAF sensors getting contaminated from debris after an air filter service. I would drive it long enough for the OBDII monitors to run and show "Pass" versus a P1000. If the Dealer cleared the codes you would have a P1000 and the PCM would start running all the monitors. If you have any big issues the monitors should pick up something as they run. (all that based on a lifetime as a Ford Tech but all manufactures follow OBDII rules).

jaycassano · Nov 4, 2024

Thanks Exfordman! I am not entirely sure what "Pass" versus a P1000 mean.

Dealer told me that If any (big) issue exists, check engine light would turn on. I also suspected various things like fuel injector clogging, MAF sensor, etc. The reading from my OBD2 scanner seems to suggest those are within "normal" range. However, I do not have a baseline for my car before the service (only purchased obd2 scanner after the fact). I suspect certain things are just "not very optimal" but still not out of range.

Variman · Nov 4, 2024

Proberly not related but have you had your 12 volt battery changed yet?

jaycassano · Nov 4, 2024

No, not yet. Could this be related? I think battery test passed. My main suspicion is either some fuel line issue or some electronics or ECU got disrupted after the service.

Exfordman · Nov 4, 2024

If you check for codes and get a P1000 that means that all the OBDII monitors have not run. Examples are HEGO (Heated exhaust sensors), Evap, Fuel, Cats, EGR, Thermostat, etc. Somewhere around 6-8 monitors. A "Pass" means all monitors have ran and the PCM/ECU is happy. I am not sure on all scanners using the term PASS. Perhaps they might say "no Codes". A P1000 should show on all scanners. . In CA a P1000 can cause your car to fail the state emission test depending on the year model and what monitor it lacks.

jaycassano · Nov 4, 2024

Will double check later. But I was able to get data like engine load, long term fuel trim, Fuel pressure, catalyst temperature, etc. So assume it's all running.

jaycassano · Nov 4, 2024

Ah, I do see there is a symbol of DCM gets crossed out on the screen. Not sure if this is service related. The AC service they did seems quite intrusive. I hope that doesn't

But thank you so much for bringing this up!

FKHeath · Nov 4, 2024

jaycassano said:
Ah, I do see there is a symbol of DCM gets crossed out on the screen. Not sure if this is service related. The AC service they did seems quite intrusive. I hope that doesn't

But thank you so much for bringing this up!

The DCM is the Data Communication Module. Has nothing to do with engine management.

DCM is what the car uses to communicate with the outside world (SOS, WiFi, status on the app, etc). There is another thread on this forum about he DCM cross out.

Joedirt · Nov 9, 2024

I haven't read the entire post of replies, but I know from history on other cars that if your spark plugs are getting older and you use manifold cleaners, that can alter your spark efficiency.

Also that MAF sensor is very very delicate item and there are some rules on what type of fluids you can put on those without giving them degradation.

One person mentioned if there is a flaw in the MAF you would get a sensor error. So that might be ruled out but it is something to consider.
Also not knowing how long they had your car idling while they were doing the manifold upper engine cleaning if that's what they did, your catalytic converter might be contaminated and could use a good run on the highway to burn all residual out. But I would look at spark plugs first.

And I am always leery of going to dealers,

I think in their training manual it says to over tighten oil pan bolts and oil filters

If you're going in for the service extended warranty stuff. I would just focus on getting your free oil change and get out. You can do a lot of that other stuff yourself if your mechanically inclined or find a good independent mechanic that you can build a relationship with. That's just my two cents.

jaycassano · Nov 9, 2024

Thank you Joedirt for the recommendations! You guys are way more helpful than dealer guys. Every time I went back complaining to them, they just claimed everything looked good! God knows what they actually checked and found. No transparency at all.

I don't know how much I can infer the spark plug condition or MAF sensor from OBD2 readings. I do have a few charts to share (these are from different trips). One shows some hybrid EV data, the other shows long term fuel trim, MAF, etc. Just sharing if any of the chart rings a bell or at least provide some relief. Some of the data looks confusing, e.g. why the EV battery power (HP) shows negative reading.

I plan to find another RAV4 hybrid to establish a baseline to compare to.

Also plan to find some independent shop to diagnostic it if I cannot find anything from data.

SLS Artemis · Nov 9, 2024

All of my vehicles fall behind every car when the light turns green. I just find it normal. My neighbor says he has the same problem.

jaycassano · Nov 9, 2024

Lol, I was comparing to my car before the service, which was pretty snappy. I get it. But I don't think this is just a placebo effect in this case.

Bcarlson · Nov 10, 2024

The first thing that comes to mind from the symptoms is there is a vacuum leak. It might be a hose with a crack or hole in it or a clamp that came loose. They removed quite a few odds and ends of small hoses and other parts to do the services, and maybe something did not get back in place.

jaycassano · Nov 10, 2024

Thanks, I will keep this in mind and leave this to independent mechanics. The original dealer declined any issue, and I tried another local dealer for a quick visual inspection and test drive. That dealer couldn't tell anything unless I pay $200 for a diagnostic which they didn't recommend either.

Big Bird · Nov 10, 2024

Any service should not make a code come up. Ran fine before service. Runs poor after service with a P0171 code... and the dealer told you this happens sometimes? Ummm. NO is does not.

jaycassano · Nov 10, 2024

Yep, totally screwed by them and I don't trust their words. I wish there is an easy way to complain/sue them. (I heard complaining to Toyota would be hopeless).

Tazio Nuvolari · Nov 10, 2024

I'd just install some new iridium spark plugs. It's easy to DIY and not expensive. They should always be replaced by 100K miles anyways.Buy new plugs ONLY at a dealers. There are lots of Chinese fake counterfeit plugs flooding the aftermarket stores and Amazon. Your old plugs probably got fouled by the "fuel system cleaning." Dealers do it different ways--some just dump a Techron type additive into the tank but others might do something more extreme like removing injectors and cleaning them, or pumping cleaner through the injectors while still on the engine. Also I second the suggestion to do an "Italian tune-up." Drive the RAV for a couple hours at 80MPH. That will burn off and blow out any crap clogging the catalytic converters caused by the fuel system cleaning.

jaycassano · Nov 11, 2024

Thanks Tazio! Taking notes ... I think my best bet is to go to a well reviewed independent shop, describe the problem, mention the great ideas from this thread, and see what they can do.

What's frustrating is how to make sure the problems are reproducible and get acknowledged by those technicians. e.g. the car whines like hell without noticeable acceleration on moderate urban inclines (where previously it comfortably drove through mountains and valleys). Dealers simply don't care to give it any acceleration tests or take it to slopes. Hope the independent shops are more approachable in this regard.

Bcarlson · Nov 11, 2024

I the first post the OP said there was a P0171 code, bank 1 system too lean . This is why I suggested a possible vacuum leak. It has too much air coming from somewhere, or the O2 sensor is not accurate.

jaycassano · Nov 11, 2024

That was DURING the fuel system service. I found it quite fishy. But the code has not been active after the service. That said, it indicates something quite disruptive happened. Dealer claimed it's not unusual because they disconnected things, blah blah ... I don't trust them.

Ruemiser · Nov 12, 2024

Hi Jay, sorry to hear about your issues. Seems the dealerships are always trying to sell services that are not sometimes needed. The AC evaporating cleaning sounds like something that can easily be done by an owner. As for the lower MPG's, check some of the basics, Dirty engine air filter. (Even though your dealer probably checked, check it yourself because I never trust when a mechanic said he did a service for me. I even chalk my tires 1,2,3,4 to be sure they rotate them as well. Caught them a few times when they didn't rotate my tires either. Check your Pressure in your tires. I recommend keeping them at 38psi. As for Fuel injector cleaning. I've never had to do this service in the past with any of my cars, latest being a 2009 CRV. The additives in the gasoline will keep the injectors clean. Good Luck

jaycassano · Nov 13, 2024

Thank you Ruemiser for the many tips! Definitely learned my lesson with dealers. (I miss my old trusted dealer in CA; first service after relocation gave me bad luck!)

Just Some Human · Nov 14, 2024

Just a thought, have changes in the ambient temperature, been taken into account?

jaycassano · Nov 15, 2024

Interesting. I have thought about temperature and AC usage. Turn on the AC does make it noticeably worse (louder noise, less power), which shouldn't be the case for morden cars? Also I don't know how much temperature would affect oil viscosity to make a difference.

Could you please be more specific?

431002 · Nov 14, 2024

jaycassano said:
Hey RAV4 users,

I recently had my car (2019 RAV4 hybrid, ~40K miles) serviced in a dealer. Dealer "recommended" a bunch of services, including A/C evaporator cleaning (with some expansive foam), and fuel system cleaning, in addition to other things like oil change, tire rotations.
<snip>

Jay

For the sake of anyone who might read this thread, there is NO good reason to have a fuel system cleaning at 40k. I got my "free" oil change a few weeks ago, and it was amazing how many things needed fixing on my 2018 RAV4. Right... tell you what, fix my hood and we'll deal with all of the other BS later. A free oil change is the dealer's way of getting access to your car. Until they fix the last screw ups, they won't see my car again.

Example: I need a new pump for my rear wiper ($250). They made the mistake of adding fluid - it works fine now. I could go on and on with all of the other BS. Example: any collision repairs are warranted for the life of the car. Okay. So, 5 years later parts of my rear hatch are peeling. They cannot find the repair records. Hmmmm... imagine that. They tried to sell me a cabin air filter for my 2007 Sequoia - it doesn't have one. FYI - learn to do some basic maintenance.

I'm responsible for the sale of 6 vehicles from this dealership. That will be all.

rberman999 · Nov 15, 2024

To the original poster, I’ve read through the thread and while there is some good advice, I’ll offer how I’d proceed as well as why. I’d start by running the car down to a low fuel level ( perhaps to the point of the low fuel light coming on). I’d then fill the car with the highest octane fuel I could find (95 octane or higher if you can find it). With the high octane fuel in the car, see if the performance improves back to roughly like you remember it (improved acceleration, better power, etc). Now the reason, the engine used in the RAV4 is an Atkinson engine using VVT (variable value timing), the engine compression ratio is roughly 14:1, (when measured using full compression stroke without lagging intake valve closure due to Atkinson cycle) BUT BECAUSE of the VVT, the engine actually runs in the 9-10:1 ratio range. If the “cleaning” the dealership did mucked up the hydronic VVT system you could be seeing a change in the compression ratio, which the increased octane could counter act. Typically increased octane is a waste and there is no improved performance associated with the added octane. So, if you see a drivability improvement then I’d start to focus on the VVT aspect of the ICE engine. One other thing to note, VVT engine issues often don’t trigger check engine codes, at least until they get really bad.

Now as far as taking your car to an independent mechanic, good idea BUT only if you bring it to a top notch mechanic that is familiar with both the Toyota brand as well as the hybrid engines. No sense in bring your car to the guy who says ”gee, I always wanted to work on a hybrid”. Good luck.

Tazio Nuvolari · Nov 26, 2024

toyoNewb said:
You say you bought a $30 bluetooth scanner. Can you tell us which one please?

jaycassano said:
The app is arguably the most popular one on Android platform. Its just called car scanner ELM OBD2.

All these ELM OBD2 devices and the apps you get from the Google Play Store work fine on Android phones but BEWARE! None of them will work on a Chromebook--even though it uses Android and accepts and loads the play store apps.

Hybrid system disrupted after dealer service?

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