2006 Prado V6 Manual - Ongoing Fault Codes

[PradoBlack Lurker Find all posts View Profile Close PradoBlack]

I have a 06 Prado 4 Litre Petrol all been good apart from ongoing Fault Codes It has done about 77.000 km mainly country and towing

The check engine light is on very few days

Code is 420 Cat Efficiency it seems to occur under light throttle (more when inlet temp lower (leass than 15 deg cel) it spent about a week at a dealer and they seemed to replace all and it worked for a few days then back again and so far that bank. Bank 2 has been fine now for several months now bank One is showing the same

The figures are always close to these:
Revs 2800 Air temp 6 - 16 Throttle position 25% Speed 90 - 100 kph

In conjunction with the light being on I get worse fuel consumption about 15 - 20%

Can anyone help??? Toyota just keep saying bring it in and we will reset it and download the freeze frames

Thank You

[tezablue Lurker Find all posts View Profile Close tezablue]

mate I have the same problem,mines on gas and the readings on the computer for the oxy sensors are normal on petrol but all over the place on gas and has them beat.hope a solution pops up . tezablue

[Bear Senior Member Find all posts View Profile Close Bear]

G'day Tezza,
Thanks for the comments you made earlier. It sounds like you are experiencing a bit of trouble with your lpg system this time. I'm fairly close to getting a Sprint Gas system installed - been booked in for a while; it would be good to hear more about the specific problems and especially if the installer is wearing the cost of finding a solution. Hope yours works out well.
Regards
Bear

[tezablue Lurker Find all posts View Profile Close tezablue]

engine fault light

pradoblack,my gas instal.is sprint gas and gas man is looking at oxy senders,but it is early days yet. Who wears the cost is anybodys guess. Keep you informed. Tez

[PradoBlack Lurker Find all posts View Profile Close PradoBlack]

Re: 2006 Prado V6 Manual - Ongoing Fault Codes

JUst adding toi my original Issues with the Engine Fault Codes
the original Issue of cat efficiency was rectified on bank 1 then a week later it appeared with same code on bank 2
the dealer replaced the cat which seemed very odd based on history but odd because that didnt fix it I raised the issue that it may be
a ECI fault but was told no
I then wrote to customer care who promply told e that the dealer said that because we used a non genuine reader to check the codes and reset them that
we had damaged the ecu (I am sure Snap On etc would love to hear that) It is funny that the codes were on before anyone touched it with a scan tool,

In addition the highly skilled customer service person told me that Butler Toyota were handling it yet we bought the car at Bendigo Toyota also just for interest
this light code 420 has been on for no less than 50,000 km and the vehicle is now out of the 100,000 km warranty and the first correspondence I had after the
warranty ended basically told me it was my fault and I need a new ECU

will keep you posted

has anyone else had such a problem ?? and does anyone know what changes to the ECU (if any) does the Cat Efficiency change,,,

regards PradoBlack

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: 2006 Prado V6 Manual - Ongoing Fault Codes

and does anyone know what changes to the ECU (if any) does the Cat Efficiency change

None... it's just the signal from a second oxygen sensor downstream of the catalytic converter to give an indication of a faulty or abnormal catalyist.

Only the sensor before the converter effects engine tune.

If the bad reading is caused by something apart from a failed cat (such as AF sensor out of spec) engine tune may change.

Sensors can be swapped between known working sensors between the banks to isolate intermitant sensor faults.


Possible issues are: Faulty catalyist, heated oxygen sensor fault (The one after Cat), AF sensor fault (The one before Cat), Exhaust leak, 3 way catalytic converter issue (Exhaust manifold)

Can't see how a ISO scan tool can damage the ECU....sounds very unlikely to me.

Mick

[PradoBlack Lurker Find all posts View Profile Close PradoBlack]

Re: 2006 Prado V6 Manual - Ongoing Fault Codes

Yeah I thought the same but one dealer techo did mention that the problem if with the AF Sensor will
cahnge engine tune as motor appears to be running lean so it corrects by increasing fuel load - this again makes sense but it appears that the
scan device that Toyota Users doesnt isolate the problem to one of another but just says that the particular feature
or code is faulty.... I hope to get a better answer this week as I took it to the Regional office in Melbourne on Thu and they took readings , Photos
and details down to do an assessments as It will be great to clear it up

[burgs Lurker Find all posts View Profile Close burgs]

Re: 2006 Prado V6 Manual - Ongoing Fault Codes

I have an idling problem wondering if any one can help with any info.... I have a 120 series petrol year 2006 done 114kms motor starts and idles 1000 revs then when hot will intermitintly rev up and down had car to Toyota there computer tells them no code problems.
They cleaned the air temperature sensor they checked resistance at the injectors and could not fault. they reset the system yet the vehicle is still doing the same thing reving high. Toyotas responce bring it in for further checking yep at my expence. "any one have any sugestions before this sends me broke "

[lingig Lurker Find all posts View Profile Close lingig]

hi burgs, am having the same problem, with my 2005 V6 manual runs along at about 1400 rpm till vehicle comes to a standstill then drops down to normal idle 700 rpm this only started occurring at about 180000 Km up till then has been totally trouble free apart from an annoying slow throttle return to idle. Have checked all the sensors cleaned the the throttle body etc to no avail. I think this a very common problem with the V6 in the Prado there have been other reports in this forum(see thread started by Jon) and the Tundera forum in the US which uses the same engine in some models. Pity this is occuring because the prado is a great vehicle otherwise. Toyota seem to be taking a head in the sand attitude to the whole thing! although it is a real safety issue.