So using my (very basic) scanner, I keep getting these codes via OBDII:

PO104 - B2/5 Hot film mass air flow sensor: Check wiring of signal line & voltage.

PO221 Fault of function monitor in electronic accelerator.

PO300 - Misfiring, Damages TWC
PO305 - Misfiring of cylinder # 5 (see currently valid STIP?)
PO306 - Misfiring of cyliner # 6 damages TWC (see currently valid STIP?)
and...
P0445 - Purge control valve (short circuit to UB or Ground / switchover valve currently open or closed).

So I presume I need a new MAS? clean or replace?

Also, I suppose this explains my accelerator hesitation sometimes w/ the electronic accelerator... what to do about this?

And I'm having a bad misfire that comes on after car is amply warmed up... sometimes it shuts down one cylinder, and sometimes 2 are shut down and then she's running REALLY rough. Will only be better after I let the car cool down and then restart. If I immediately restart - misfire coming RIGHT back.
I have replaced plugs & wires recently, used a couple of high quality fuel injection cleaners (Lucas, Techron), recently had a new fuel pump, filter & sending level unit. The only other things I can think of would be a bad fuel injector(s) or ignition coil?

And what is the Purge control valve? I'm going to look it up right now!

Car is a W211.065 with the M112.949 motor at 211,000 miles!

Please help! Thanks!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

First thing look closely at all the rubber hoses to make sure there are no leaks anywhere. Simple, cheap fix if you find/fix rubber hose leaks.

__________________
Jim

Rubber hoses... so not vacuum lines then?

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

I think he means both vacuum and others like the EGR hoses.

Have you cleared those codes? If not, do so and then drive a couple of days and rescan. Also, trouble codes often cascade which adds to the confusion.

You can clean the MAF sensor but you need to remove the insert from the housing. Unless they've been replaced, they are probably 5 pt torx security fasteners. You can get a set of those bits at PepBoys. They also have CRC MAF cleaner. Usually, when it begins throwing codes it's dying. If you decide to replace it be sure to get the correct BOSCH MAF from a reputable source (usually NOT eBay).

The purge valve allows gasoline to be diverted back to the tank when the engine is running too rich. Usually right after a cold start. It's a solenoid valve and you may hear it make a ticking sound.

__________________
Good luck.






1998 E320 Wagon

I have cleared the codes, and they do return.
I have heard a clicking sound in the engine bay. So this returns fuel to the line when running too rich.... I have had a faint gas smell sometimes, and also, would this be why when refueling, the DAMN pump ALWAYS clicks off?

Also, no, how involved is checking/clearing all of those vacuum lines? What would an expected cost be if had this one at a reputable mechanic?

ANy clues as to the misfiring?

Thanks SO MUCH you guys!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

The gas station annoyance is due to the charcoal canister not being able to vent the air inside the tank as it fills up. The clicky sound you hear from the engine is the vacuum unit for the evap system (its marked MOT) - remove the hoses and clean it with some WD40 or carby cleaner.

When I had these misfire issues the problem was bad spark plugs - I changed all 12 of them.

Most people have also reported that the cats had broken up and plugged the exhaust which caused the misfire.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Thanks for the info!

So I presume that I need a new charcoal canister? I'll do some research on that.

Okay, I'll make a project of cleaning the vacuum lines. (i have alldata)

I had the cat's welded some number of years ago, and there was a rattle-like sound for awhile.. but it has pretty much "dissipated" on it's own? I have a feeling that might be the issue there... Probably need to be replaced...

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

One more thing...

so the purge valve is the charcoal canister, correct? What is it's function, to collect any gasoline vapor when refueling? Is it's replacement that important or necessary?

Thanks!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

The evap canister is a trap for gasoline vapor and it constantly keeps the system under a vacuum (managed from the intake manifold and the valve marked MOT) to keep the tank and associated parts under a vacuum.

The system self checks itself by closing off a valve on the charcoal canister and engine vacuum is applied to the system - if the pressure sensor does not register negative pressure in given time it will set the error code for it.

In usual cases overfilling (topping off) fuel or pouring some additive without a funnel in the filler throat causes the evap canister to flood with gasoline or the additive you were trying to pour in.

This is very bad and can cause permanent damage to the canister or the valve on top of it.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

First thing I would do is swap the coils around and see if the mis-fire moves. The P0104 is telling me you may have a bad throttle actuator. Deal with the mis-fire first.

What is the difference between the:

Regeneration Valve - Fuel Vapor Recovery

& the

Purge Valve - Charcoal Canister??

They look like the same part?

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

the regen valve is in the engine bay and meters manifold vacuum to the system, the purge valve is actually on the charcoal canister and closes off to make the system air tight.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

So would they likely both need replacing? Where is the charcoal canister? near the fuel tank I assume..

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

At the moment you dont have a code for them - It comes up as gross leak or small vacuum leak.

At first you need to solve the misfire issue. Did you inspect the spark plugs?

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I need to order that spark plug tool

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)