I have a 00 E320 and I am getting these codes. The car runs great and gets good gas mileage still. Any ideas as to what to look for? I have a bad cat (rattling) can that cause this?

 

it only deals with the air/fuel mixture.

some causes are: air leak, fuel injectors, fuel pressure regulator, or wear to the engine if you have high mileage.

this fault can be erased and ignored if your engine is not shaking.

no, it has nothing to do with the CAT. that rattling means the catalytic converter has made a self multiplication and division. replace it.

bring the car to a workshop with HHT or Star diagnosis and reset the stored adaptation data. also adjust the ignition timing and fuel injection quantity.

the "check engine" light isn't on is it?

try bleeding the air from the fuel rail as well.

 

Sleepwalker,
Thanks for the reply. I'll have to look closer for a vacuum leak. I haven't found one yet. I'll run some concentrate fuel injector cleaner this weekend, I'm taking a 1000 mile trip. Is there anything special that I should look for on the fuel reg? The car only has 55K miles on it. I hope that is not concidered "high mileage"! If it is, the car has to go!!!
Is the engine shaking?, it is vibrating at idle. However, right now I suspect that is coming from the cat rattling in the case. You only feel it in the steering wheel, you can't see the engine shaking.
The check engine light has been coming on. I have a program for my lap top that I use to turn off the light. The program I use use developed by Alex Peper, you may have heard of him. When I reset the light, it takes about two weeks before the light comes back on.
How do you bleed the air from the rail?? I assume by removing the shrader valve cap and purging it there.

 

as of the oment i am not sure if your engine is 104 or 112.

i can only guess it was 112.

if the engine is not shaking then there is no air leak.

the first step that you want to do now is to replace the catalytic converter because the downstream oxygen sensor detect the lean and rich mixture... hence cause the fault code! if the catalyst doesn't function well, then the O2 value is beyond the acceptable level.

yes, from the schraeder valve. try to drain half liter...just enough to purge any air inside.

 

try to replace the air flow meter.....
is always cause the problem....

 

Any great ideas on where I can find a Mass Air Flow sensor. That might be my problem. I took the car down to get the radiator flushed and the oil changed and they inspected my air filter. I knew I needed a new air filter so I bought a brnad new K&N and I am still getting the same error code the P0170. So they must have done something to the MAF. That's all I can think of because this is too conincidental.

 

May be related to K&N, common MB issues with MAF. Mine failed at 60K miles. The MAF is about $300 to 400 at the dealer. Also check for any vacuum leaks between the air box and the MAF/intake manifold.

Have also heard that bad MAF may also cause your CATs to fail prematurely (very expensive) as too rich a fuel mixture from a bad MAF may result in fuel detonation inside the CAT. Best to use factory MAF and air filter if you want to pass CA smog.

 

thanks to all of you in this forum, i have aclk320 with 30k miles and ck engine lite came on after i had an oil chang from local mech. the codes were p0170 and p0173. i read the parameters with a code checker and compaired to my bmw. i noticed that ltftrm1 &2 were stock on 34.4 while the bmw was -.01/ i reset the codes many times but it came back after 24 miles. i took the mas out/ unscwred the 2 hex screws and took the element out and cleaned with no residue electronic spray cleaner / sprayed the heck out and put it back. the ltftr's are at 18 and check engine is gone for 150miles. (you have to reset the codes) good luck.

 

The problem is in MAF. To properly clean it, MAF insert must out and cleaned with CRC. Less than proper cleaning will make check Eng. light come back again.

 

Hello there,

I'm new in this forum. I have 98 E430 and it has check engine light with code p0100 (MAF), P0170 and P0173 fuel trim malfunction B1 and B2. The engine run good at idle speed at cold orhot (normal temp ~90c). Howerver if I drive forabout about15 min on the freeway (70 -80mph), the car suddently cannot accelerate; the speedomer dropped and the engine felt like starving fuel and jerk a lot. I checked the LTFT while it happened, theLTFT for bank1 and bank2were over 35. I replaced lots of parts but this car still have the same problem. Here are parts I replaced: MAF, Throttle actucator, intake flap switch over solenoid, O2, intake pipe, spark plugs, MAP sensor, fuel filter. I checked for leak, but vacuum reading is good. All parts I replaced are from dealer. I run out of idears. I suspected the ECM but not quite sure.Anyone have seen this problem?. Please help!