Code 170 & 173
 

on my 99 ML320, CE light is on and getting codes 170 and 173 which is fuel trim banks 1 & 2. I was getting this and several codes and replaced MAF sensor and all cleared up for about a month. Now the 170 and 173 are back. Also i will cough and sputter on acceleration and performance is bad. How do i correct these codes?

Thanks!!!!

Did you replace the MAF with a complete Bosch factory NEW unit?

No it was a refurb from NAPA

That is still most likely your problem! those CHEAP non-Bosch reman units are JUNK.

You need a new complete Bosch unit...we replace those re-man units after 2-3 months of service all of the time!

Thanks! I have been told that i need to get all reprogrammed after installing the new one. It this right or can i simply by a factory unit and i am good to go?

No re-programming....computer will re-adapt if the info is correct from the sensor.

Agree with Doc on this one. Bought a so called "brand new" one off ebay. It was a complete diaster. It was not original and not new. Looks like a refurb with off-brand casing. My 2001 ML320 ran worse with it than my original one. Fortunately, took action quickly with Paypal and was able to re-coup some of my money (I sent the unit back to the seller). I learned my lesson on buying parts.

I spent the money and get a genuine Bosch OEM from my dealer. The car runs much better now. I know the dealer and MB pricing on MAF is a ripoff. Driving a Benz means you have to put up with many of these ripoffs. I could have saved $100 by ordering from Duvall had I known them then. Anyway, don't settle on anything other than OEM for these electronic sensors. I can see using some not so critical mechanical parts from non-oem. But MAF is not one of them.

As long as you purchase a new genuine Bosch aftermarket MAF, you're OK. It does not have to be OEM MB branded; and the Bosch part is way cheaper than the MB branded part.

Thanks. Good to know that. How much does the generic Bosch part cost? What's the part number? Duvall charges $290 for the MB one.

I'm sure that Phil at FastLane can get it for you. Mine was a little over $200 from another supplier a year ago.

If Phil can't help you, let me know and I'll look up the Bosch P/N for the M113 engine - which should be the same for the M112.

Go here...http://www.********.com/

They confirmed with me that the Bosch ones were 100%factory. I have bought from them before and always been top notch. I trust their info. On their site, the ones that say "reman" are indeed "reman"

I picked up a Bosch reman @ Advanced/Discount Auto...
 

...a couple of days ago... Installed it and all my problems, i.e. not down shifting correctly when passing, etc... cleared up... CEL went off after driving for a few minutes, letting it sit and restarting, so I'm happy... Nice thing about Advanced/Discount is the 1yr warranty on the parts... If it goes bad in a couple of months, I'll just take it back & get a new one... With it being a 5min install plus the warranty, I'll take my chances... That is, unless someone can point me to a parts store/supplier that can get me a NEW one for under $200...

But that's just me....


SLN

Had CEL error codes P0170 & P0173, Fuel trim Malfunction, Bank 1 &2
Replaced mass air flow sensor insert for $129.00 Ordered from:
http://www.germanstar.net/163f.htm. Seems to have solved problem; no drivability issues.

Where can I get the tool for the screws of this insert?

Thanks,

Rene

You don't need to remove those screws. I made the same mistaken assumption you did. Read this.

http://www.peachparts.com/shopforum/showthread.php?t=148653