audi a4, code p0171

[muffin]

hi all,
this is my first post on the forum! :beerchug: got to say this is a cracking vw/audi site :notworthy

now.. i have a audi a4 2.0se 51 reg multi-tronic.

i had the eml come on and got it checked out.

code p0171 is present :(

anybody else had this code appear?

how should a go about solving this?

the mechanic pointed out the oxygen (lambda) sensor may need replacing. he also said something about a 'lambda injector' is this another term for a lambda sensor?

your help would be appreciated :grouphug:

[adamss24]

acording to Autodata, it says: code p0171, system too lean bank 1= intake/exhaust leak, AIR system, MAF/VAF sensor, fuel pressure pump, injector(s), HO2S. I would check Lambda/oxigen sensor first but this will cause a rich mixture, though ! I think your MAF its on its last legs and will need replacing too, also you did not mention mileage and if thats the original maf...Could also one of the injectors as well. Get a verry good injector cleaner and pour into the tank and give it a good blast on the motorway. Hope this helps.

[muffin]

thaks for the reply :fing02:

mileage on the clock is just over 73000, had it serviced 1000 miles ago. i do not know if the maf has been replaced on the car, so i presume to have it replaced soon. is the maf cheap? a rough price? i use injector cleaner (redex) once a month, have done so for the past four months. the light came up about three weeks ago, had it reset soon after it came on and now its on again :confused:

how do i go about testing the lambda sensor? where abouts is it located?

[diogenis]

muffin I would check for a vaccum leak first. I had the same code on my S4 and it was a leak. That is usually the cheapest fix. As far as checking the lamda sensor you need a vag tool. I have one and it is the best tool i ever bought. Then you need a bentley manual for your car. With those two and some time to study you will be able to troubleshoot the problem.