Cleaning the MAF P0174
 

I threw the 0174 code which is bank 2 running to lean. I got plenty of advice telling me to clean the MAF sensor or replace the o2 sensors. Which do you recommed and if so, is the precat or post cat. How long does it take to replace the o2 sensor or how much would a shop charge


Say I do clean the MAF...do I just take the whole thing out and spray it down with the stuff from autozone? Is there a DIY?

Compliments of the one and only weasel56...

I had the same prob 3 weeks back...

Quote:
Originally Posted by weasel56
[I]Quote:
Originally Posted by richirich
Weasel56 - I hope all is well with you!!!

You seem to be the expert here on the forum with this type of stuff.....

I was driving and my yellow ses went off.....after a day it cleared....then today went back on.....so being the freak that I am I went to the boys at my local autozone...they hooked me up to the OBDII and I got a p0174 - here is what it read.....

the pcm has determined that during testing the fuel system for bank 2 was too lean.

I'm thinking a new 02 sensor after the cat....what are your thoughts and input. any help here is greatly appreciated.

Thanks,

Rich


Not a problem man. :thumbup:

The post cat o2 sensors don't read the fuel mixture, only read of the cat converter efficiency... so it wouldn't be that. Sounds like you have some unmetered air coming in somewhere. According to the SAV profile you got a 3.0i, so I would first suspect the intake boot to the throttle body/idle air motor. You can just reach back there and feel for splits on the outer bank of the turn on part #8 where #9 is pointing in this picture.
http://i140.photobucket.com/albums/r...icture1-20.png

If that is fully intact with no splits, it may be the cyclone valve (crankcase vent valve) as that is another of the more common leak points as it gets some age and mileage on it. As you can see it has quite a few hoses, but #4 is the one that is the first to fail as it is the rubber hose for returning the separated oil to the crankcase, and the rubber turns to a play-doh/clay like consistancy and will split. If that is the case, you should change the whole valve/hoses setup. (1,2,3,4,7)

There are DIY writeups hidden in the forum for both of these parts as well.

http://i140.photobucket.com/albums/r...Picture2-9.png

Hopefully one of these gets it.



Rich:thumbup:
__________________
Richirich
***YOUR FRIENDLY NEIGHBORHOOD MODJUNKY MAN***

I just had an issue with the MAF sensor. We tried cleaning it but it wasn't successful. The tech said there is a microchip inside and that usually goes bad? Ended up costing almost $400 for the new MAF sensor. I don't know if that resolved my issue as the X is still in the shop.

P0174/P0171 System too Lean (Bank 2/Bank1)
I got plenty of advices telling me to clean the MAF sensor, in fact I've used special designed (CRC SPECIFICTLY MADE FOR AIR MASS SENSOR CLEANER) And I even replaced all 4 oxygen sensors under the car, but unfortunately did not give me an happy ending because right after I finished and headed down the road, the car threw out the same: code P0171/P0174 again with my service engine light on.

I wonder if there's a very easy positive way for sure to find out if your mass sensor is totally bad and needs to be replaced.

01 BMW X5 4.4i M62

I had loads of problems & it was the MAF. They go at 60k miles. take it off (2 min job) & spray it with tons of contact cleaning spray and the connector & lead. Mine was 90 % right after that which told me it needed a new one. Get the part no off it & buy one online & fit it youself. Mine cost me £ 100 over here - dealer wanted nearer £ 300. I really would do this before messing with the more technical stuff.

Good luck.

Nige