P0170 code - Should I get this tested?
 

I have a P0170 code happening again on my 1999 C-230. From searching, I see that the two common reasons for this code is the air mass sensor or the fuel pressure regualator.

I replaced the air mass sensor about 18 months ago (which instantly solved the last p0170 code problem), so I wonder, do they go bad that quickly? I drive lots of highway miles, so the new one probably has 50,000 miles on it. I also noticed that the large hose entering the air cleaner box has a black tar film in it. Anyhow, should I have the adaptation codes read or just replace the air mass sensor replaced again? Thanks for the help,

Don

PS - what do they charge to read the codes?

I see where guys are having luck lately by simply cleaning the MAF sensors with some of the new MAF designated cleaners...Real simple to do and I did one last week ] actually my own] that worked out fine [ and it was mas-film, not hot-wire, so I was impressed]
the one I used way CRC MAF Cleaner ..read the directions, gave a shot and cleaned it up real nice. The before /after was impressive.

Might be worth a try....that's how I felt about it, anyway...
Was $6... the ECU will re-adapt on it's own if it solved the problem..takes a few drive cycles.

Thanks for the suggestion. I tried it and the car runs a lot better now. The light hasn't turned off yet, but the engine is smoother. Unfortunately, I found a heavy film of oil all over the sensor, so I'll have to start another thread about that. Thanks again,

Don

Haven't installed a KN Filter , have you ?????

No, what's a KN filter?

It is an after-market performance air filter that many guy use , not knowing that they raise hell with Benz HFM MAF sensors due to the fact that they are an oil bath type filter. That would explain your condition, so I have to ask on that type of complaint.

<<Unfortunately, I found a heavy film of oil all over the sensor>>

My first check on that would be to check for possible crankcase oil capacity over-fill.

where can i buy CRC MAF Cleaner from?

Pep Boys for one.