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Yaris D4D no power past 3000rpm

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Its good to be back. My Toyota history is a Yaris mk1 1.3 SR then a Corolla T Sport and now Yaris D4D mk2 pre DPF.

I was getting error code P0487 so had the EGR blanked off and professionally mapped out of the ECU. 

My problem is the car is fine up to 3000rpm but struggles to go above this. No EML and no error codes recorded. 

The maf sensor has been cleaned and air filter box cleaned out and new air filter fitted. Today I disconnected Battery for 15 minutes to totally reset ECU. 

Tried it tonight by driving to retail outlet and no change. When I returned to car 15 minutes later the power was back and I had full pulling power i.e. revving over 3000rpm easily. Turned round to return home and back to 3000rpm limit again. The car has 87K recorded miles. 

Any advice what to concentrate on would be most welcome because this is spoiling what is a great car.

Many thanks


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it could be a number of things, a stab in the dark i would say its something on the boost control side/ a vacuum leak

i would have a look and see what the map sensor is reading with an obd2 reader under load

Is it burning Oil, is there a lot of Oil in the intake piping ?

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Blocked fuel filter

Failing fuel pump  (unlikely no warning codes)

Blocked catalyst - do you do lots of short journeys..? 


Failing exhaust sensor (unlikely no warning codes)

Is the Battery original..? If so may be FUBAR.


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I have, what sounds like, the exact same problem, except that I haven't tried to map out the EGR.  Assuming you're on the same ECU as me ( DLP90 D4D Mk2 Pre DPF car ) then, the short version is your ECU may well be broken and needs to be replaced.

Long version:

I have no power above 3000rpm which is because the car is in 'limp mode' because a P Code is a Powertrain fault code ( We'll get to your modding this out - spoiler: you didn't ( 'If' my assumptions are correct )).   I used to be able to clear the code and the car would instantly get it's power back above 3000rpm.  The code started coming back more frequently and now it reappears the instant I start the car. Much more importantly, I noticed oddities with some of the sensor readings, e.g. MAP sensor rarely reports less than ambient which is wrong e.g. when the throttle is closed or idling, Throttle sensor reports only in the 45%-49% range yet below 3000rpm the car drives ( and idles ) perfectly and the throttle and the manifold pressure both tested fine.  Also the car starts fine which it shouldn't do with those readings. Load percentage is hit and miss as to whether it gives any reading at all or just stays on 0.0 even under heavy load. 

After a month I bit the bullet and put the car into Toyota who didn't find anything wrong with the engine itself except for the fault code and also picked up on the strange sensor readings.  They referred me to a TSB where this is a known problem with the ECU failing and now I have an ECU on back order - 700 quid mind + fitting.  I could try to go after market or breakers but, to me, that is just trading one problem for a slew of unknowns.

If ( and I stress 'if' ) you have the same problem as me, the P0487 ( which you've now masked ) is just the more obvious symptom and the fact that it's an EGR related code is irrelevant.  We see in my car 4 different electrical glitches all at the same time - all driving related but driving is largely unaffected?  Not likely.  I don't know what your mapper did with the EGR logic but between the mod and a broken ECU it's reasonable to see what you're reporting even if you can't 'see' the P0487 anymore.  Doesn't sound logical but that's the point.  The ECU logic is broken so we see things that don't make sense.

Just my 10 pence worth based on my own experience with my little Yaris.




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