Bought last week and CEL :(

Posted March 30Mar 30

Hi all, bought a van last week and super happy with it this is my first post on the forum after going through lots of information I’ve found it a real help so far.

i was really wondering if someone might be able to shed some light on this issue I’m having before I take it into a garage for them to diagnose.

its a 2008 anh10 with the 2.4 petrol engine fwd.

it threw the code p0171 and has been running lean on acceleration ever since although still drives well and seems to get decent MPG still. Starts first time without any issues.
since I removed the code it hasn’t reappeared but I have been monitoring it and it’s still not running right.

the calculated load of the engine won’t go above 70% and everytime I accelerate fully or even half peddle the LTFT jumps to 25%.

I removed the MAF and cleaned it but didn’t seem to make any difference so I’m guessing it’s something to do with the fueling?

just wondering if anyone could shed some light or let me know some things to check before seemingly having to fire the parts cannon and the fuel system.

thanks all!

March 30Mar 30

I was getting P0171 "system too lean (bank 1)" also and cleaning the MAF didn't help - the error would come back.

What fixed it for me was changing the front Lambda sensor which, on mine, was a struggle as the previous mechanic had forced the sensor into place and had damaged the thread.

An M18 x 1.5 tap and die cleaned up both the thread on the exhaust and the new sensor which I purchased - I would warn to be on the lookout for ones with the correct plug on the end as the cheap ones come with bare wires that need to be housed in the original socket (as the supplied ones don't stand a chance of fitting) and are bound to cause issues.

I ended up getting this one:

https://www.autojapspares.co.uk/toyota-alphard-anh10-anh15-24-front-fuel-ratio-sensor-34437-p.asp

Which is rather expensive but arrived quickly and was a straight plug in.

I also changed the fuel filter (see below) and the air filter - which may have helped but less so that the sensor I would say.

Suffice to say that the emissions that it failed its MoT test on it now passes.

Out of interest what are you using to grab your figures as per your screenshot?

Edited March 30Mar 30 by Gamith
To ask about source of figures.