Rav4, ECU and Carbon Black Smoke


My 2008 Toyota Rav4, 2.2 D4D with 88264 miles on the clock has a problem.

I picked up the car from Toyota last week.
Now EGR valve and intake manifold are clean, and the car has no power loss at 1.500 RPM anymore.
The 5th injector is clean as well, as the P1386 code came up, and a new air filter has been installed.

The main problem with this car is the black smoke from the exhaust when I accelerate, less when idling.
A full acceleration (no gear) gives me a big and long puff of carbon black smoke. It’s rolling cole!

The smoke increases if I use the AC. I can’t drive this chimney :confused:

People at toyota told me they found out the Eprom has been modified (second hand car), so their guess is that ECU mapping is the cause of the black smoke.

How can I know if ECU has been mapped?
Has anyone had a 2.2 D4D Rav4 and a smoke problem before? What could I do next? What to check?

Why didn’t the Toyota dealer flash the ECU back to factory?

Why didn’t the dealer offer to replace the ECU with a new one with a factory cal?

Generally it is difficult get the dealer not to over write a tune with factory cals when in for service.

It may not be a factory chip. If its an aftermarket performance chip then the dealer may not be able to reset it.

Most (maybe not all) of those went away in the 90’s. There are vendors that sell “chips” or “tuners” that just plug into the OBD2 port, but these things do nothing from what I’ve seen on YouTube. I’ve seen a few cut down showing essentially nothing useful inside.

Either the ECU was sent out to be re-mapped or someone soldered in resistors to screw with the sensors so this diesel runs extra rich. Either way, the dealer should be able to recognize if the ECU’s been tampered with and download the proper calibrations or replace it with a new ECU.

And why someone would spend money on a custom ‘chip’ for a 2.2 L Rav4 is beyond me…


For the same reason Volkswagen used improper software in its diesel cars, for more power and better fuel economy.

Sure, but for this? Camaros/Mustangs/Corvettes/etc., sure, but there’s precious little to be gained for either power or economy for that Rav4.

The one I’ve found claims 35hp gain and better fuel mileage, should be able to reflash to stock

You could stop after the word ‘chip’…I don’t care what vehicle…they are a complete waste.

I wasn’t sure when the cut-off date was. I looked into them when they first came out and very quickly realized what a rip-off they were.

80’s vintage GM cars had EEProms in sockets in the ECU so you could swap EEProms with a different calibration sets on them. Hence the term “chipped” to refer to performance ECU mods. Not all ECUs were built that way but the term stuck. Since most modern ECUs can be updated at the dealer, the term “flashed” started popping up. Plug in a device to the OBD2 port and you can download a performance calibration file set. Not all cars allow for that.

Nearly all just bumped up the spark map so you HAD to use premium fuel. Some removed the speed limiters and rev limiters. Turbo boost was electronically controlled on some cars so there was potential for big increases. Buick Grand National turbo V6’s benefited quite a bit.

I had a couple of friends at GM that owned these cars with performance EEProms (direct from GM’s special development group). They called the EEProms the “FBI” chip because supposedly the FBI ordered a number of these cars un-marked with the Grand National badges deleted and these chips.

Cars that benefit the most from an ECU performance flash are still turbo cars. Raise the boost, and you can get big power gains in 5 minutes… until you break something!