97 C230 code P0170 in 01 & 02
 

Hi!
I had this code come on now for a while, oc2 was change and code P1070 in 01 & 02 keep coming up, usually after the car has run for quite a while. I saw on the tech post references to the air flow censor, and my guest was of the egr valve or the thermal switch to the valve, is this correct and can you tell me exactly what it may be and the fix?

Thank you

use the SEARCH engine on this forum, type in P1070 and you'll get; instructions and where to buy plus additional diagnosti info.

P0170
 

Thanks Ethan

Seems that it's the same thing that I just fixed on a Grand Marqui, just needed some cleaning of air intake. I would hate to replace the air flow meter unless I have to
Thank again

I had the same code and Check Engine light go off on my 1998 C-230, the big thing for me was the funny way the transmission was acting.
I didn't read or check adaptation values and gambled on the MAS sensor, which in deed did fix my problem.

I always thought intake cleaning or repairng of the MAF/MAS sensor wouldn't work, but I did read on one forum ( maybe here or at www.club202.com) someone posted directions on how to attempt a repair on the MAF/MAS.

p0170
 

So far so good my light hasn't come on for afew days after puting the oc2 censor. No isues with the trainy so far! By the way no free speech at (www.club202.com)

What is an oc2 ??

co2 sensor
 

sorry my mispelling, I meant the Lambda sensor or the oxygen sensor (O2).
Light came back on today,I just clean and cleared code ,will see if that helps.
By the way sl 600 cruzin posted on 4/28/05 on low fuel pressure and the fuel filter , that was my original diagnos, got a fuel filter last week ,still have to install it.

That's better! 02 :)

Oxygen = O2 ;)

02
 

Thank you I stand corrected, and I installed the fuel filter ,I'll let you know if it does the job (p0170)

Your code means the system is at its max adjustment and can no longer adapt to an air/fuel imbalance..
This can be caused by a lean condition, in which case the vac lines shoud all be checked for possible leaks [ on that chassis , check around the front of the engine, the line that go to the switch-over valves for EGR]

Also can be caused by a rich condition . In that case , a possible is the fuel regulator has a ruptured diaphragm . This can be checked by taking the hose off the reg. and looking for fuel in the hose.. there should be none.
A fuel pressure test is in order to complete this test.
And then , there is the possibility that the MAF is not reporting the correct intake air mass , in which case it is faulty [ a good possibity].. but , the proper sequence is start with the vav leak/fuel pressure first.
Adapatation specs are used for this diagnosis, but that requires equipment , so for the diyer , do the above sequence .
You may just have a bad fuel feed, so you will know with the new filter....
" 02 Sensor "is the proper terminology..

02 sensor
 

The intallation of the fuel filter has done the job in conbination with cleaning of air sensor , used electrical contact cleaner, will be back when next problem comes up, and thank you all that help in resolving my issue with this p0170 code, for now i will work on my spelling!:)

Go to your room & write:
Oxygen Sensor = O2 sensor.
100 times !

97 c230 p1070
 

Man!!
Spoke to soon!
Fifth & six grade used to make me do that untill I dicided not to do the lines!
The teacher didn't know what to do anymore, another kid had a nervous break down in class and that was it for lines.
now code p0170-02 & p0133 -01

Stop throwing parts at it and have the adaptation codes read.

97 C230 code P0170 in 01
 

Hi! John Shellenberg
Adaptation codes? I use an Obd II code,I guess I should have the mech. look at it. My car idles correctly as far as I can tell, my last try is going to be the second 02
The car did adapt and now no code, the fuel filter must of been the culpit.
sensor.:freak:
1997 c230 120,340 miles

That code indictaes a fuel trim problem. The adaptaion values will show how the system is compensating, rich or lean. If they are pegged at the 1.32 compensation value, then it's likely that the Air Mass Meter is faulty. If they are pegged low at .67, then it's likely that the fuel pressure regulator is on it's way out.

You need SDS to read the values.

Suppose the fuel trim adaptation value is 1.32 or over 1.10. Then connect a "known good" Air Mass Meter and drive the car, reread the values. If that corrects it, install a new AMM. This is what a good mechanic would do. If the problem is NOT solved by the AMM, then reinstall the unit. By paying for a solid diagnosis, you'll save a ton on replacing good parts. It sounds like you'll eventually replace both O2 sensors and a bunch of other stuff before you get the problem solved.

Why did you replace the EGR? The code P0170 is fuel trim and the devices that commonly fail that regulate the fuel trim do not include the EGR.

Also, the O2 sensors have their own series of codes, the P013X codes. If you're not seeing those codes, why are you starting your diagnosis with replacing O2 sensors?

I know that a vacuum leak can pop up a P0170, but on that car, it's the AMM or pressure regulator about 90+% of the time.

c230 p0170
 

My first codes about a year ago where for connection on the secondary o2 then fuel trim and primary o2, yesterday the car add no code, the fuel filter was over due by 40.000 miles. I couldn't feel any bad idle so I didn't think of any vacum leaks,the fuel trim and o2 codes did give me the impresion that of a low fuel to air ratio and the Egr valve came to mind since the code came on only after some fair amount of driving and the codes is a Emmission one, the valve wasn't replaced. I'll resend the secondary o2 that I ordered and I am all the wiser for now. the car been this young now I figure the o2 must be due for renewal for the fuel injection to work correctly, my privious car, 84 Audi 5000 285,000 miles had the o2 light come on every 40,000 miles or so and just add to reset the switch behind the dash, changed it only once, I'd figure it be simular. I am going to need SDS to read the values next time If I sense it really needs it, so far everything on this board has help to narrow it down without extensive equipements and thanks again.

I'm having difficulty with reading your post, so I'll wing it...

The O2 sensors are not a "periodic" replacement item as it might have been on your old Audi. My own 1998 C230 has never had an O2 sensor replacement, and will not until they are required. The emission and FI systems in your 1984 Audi and your Mercedes have little in common as far as diagnostics are concerned.

As to idle quality, a failing Air Mass Meter often gives no idle quality problems and when it's really on it's way out will usually give a hesitation above 4500rpm or so.

It sounds like you prefer to keep throwing parts at it until the codes are cleared. Good luck.

97 C230 code P0170 in 01 & 02
 

Thank for the hint on what to look for when the air mass sensor goes. The only small hesitation that I can detect is about when the car just warm up at idle if that indicative of anythings!

p1070
 

I'm back to let everyone know that my proplem with the engine check light seem to be resolved . :dj:

So, are you going to tell us the cure, or is it a deep, dark secret? ;)

p0170
 

Its not a secret low fuel was due to FUEL FILTER!!!!!!:dj: :dj:

:) To up date you on my Benz , I did purchase a air mass insert for $99 and run the car in second and third gear to reach 4500 rpm and voila! The car works like a charm, now the proplem i get is the second 02 sencor give me when it get wet a fault code, I tryed to replace it but could not budge it. my question is there a special wrench to get a good grip on it?
by the way thank you all for your informative insights.