Javvy

I did change all the magnets....link below.
...

https://mbworld.org/forums/c-class-w...t-6-codes.html

So all the magnets are new......the check engine light popped...for some time it would come on and then go away.....so I didn't pay any heed to it....but now it is stable even tried resetting no use.....

please provide input on what sequence of diagnosis should I do......

thankx
Javvy

Glyn M Ruck

Too rich at idle Bank 1.

You need to make sure that the air cleaner is sealing properly on the MAF & that you have no inlet air restriction, clean filters etc. This is not a vacuum leak or you would be running too lean.

I find it hard to believe that you have O2 sensor or MAF trouble at your mileage but I guess it's not impossible.

Please do me a favour & check that you have no broken swirl flap or runner flap linkages on the inlet manifold. Happens on early M272 engines.

Javvy

OMG, glyn you are the man.....the rubber gasket that is between the manifold and the air fliter housing had a major sheer when I was replacing the filter the last time....so I kind of used super glue to put it all back togather and made sure that it was perfect.....may be that gasket has a small leak and thats why this ghostly check engine light.......would you happen to have the part number for that gasket......I will also check all of the above that you mentioned....

appreciate your help Glyn....

javvy

Javvy

Glyn....I removed the air filter cover and remembered that I did replace that gasket but yet did a double check on it being cracked again, but it was all good. Next I chcek the swirl flaps and the shats, touched then physically with my fingers and tried to wiggle them but they are also all good.......reinstalled the air filter cover real tight and reset the code using the ODBii scanner, the code seams to have disappered for now and hasent come back.......next will get some body to hit the gas pedal in neutral and will check out the shafts in actual motion...i assume they should have some movement when gas pedal is depressed...correct???

Phister.....for the parking brake the cable was super loose, so loose that when disengaged would not even come close to the ebrake switich and also the switich was dislodged from its bracket......reinstalled the switich and tightened the cable all is good now....

thankx all for the help.

Javvy

Glyn M Ruck

Javvy - the inlet manifold runner & swirl flaps are vacuum operated & only move when certain conditions are met with the car running. Pleased you have no broken linkages because there are no spares available & a new manifold is something stupid like $1400.







Hmm! I'm starting to wonder if we don't have a clogged Cat on one bank or that the EGR circuit is playing up. Why no codes

Javvy

how long does the cats last anyways.......and how much $$ do they cost.....let me observe how it behaves not that the codes are reset....

thankx glyn for all the help.

Javvy

Javvy

OK The chcek engine light is back on...........what do I do? where do I go from here???

Please help.

Javvy

Glyn M Ruck

OK - now read codes again. I want to see what fresh ones come up. Your Cats are covered to 80K miles in the US by law so Benz will have to replace FOC.

Our dilemma here is that we have one MAF feeding/reading both sides of the engine. So fuel trim airflow measured by the MAF will be signalled to the ECU as equal. However we have the post Cat O2 sensor telling us that we are rich at idle on Bank 1. This tells us that we are over injecting fuel to Bank 1 under idle conditions. The question is why?

Possible reasons with above already checked - e.g. manifold controls:

Bad Cat not cleaning exhaust stream or clogged & creating back pressure.
Bad reading from post Cat O2 sensor Bank 1
Bad reading from pre Cat O2 sensor causing ECU to over inject on that Bank i.e. rich.
An incorrect engine temperature reading by the temp sensor but that should effect both Banks equally like the MAF.

The trouble is that all these things should throw codes apart from a clogged Cat condition.

Javvy

thankx Glyn...I will pull the codes again and post. I just clicked 82k miles so I guess I will be out of luck there, but will still try to push the dealership goodwill if need be......from what you are saying.....I am trying to look at the worst case scenario.....if the Cats are bad what would be the $$$ damage....let me do some research....

javvy

Javvy

Glyn pulled the codes got 4 ....P2188 & P2188pd (Bank 1) and P2190 & P2190pd (Bank 2).......does this make any sense.

please let me know

javvy

Glyn M Ruck

Javvy

P2187 System Too Lean at Idle B1
P2188 System Too Rich at Idle
P2189 System Too Lean at Idle B2
P2190 System Too Rich at Idle

I think there is some Benz specific coding sitting behind these that we can't read.

This is where a dealer has the advantage. They can try things. So - you either get this car into a Star or if you want to try things swap upstream O2 sensors & see if the problem changes sides or replace the Bank 1 upstream O2 sensor which might be a waste of money. Original problem.

Now that we are getting too rich on both Banks of course the MAF once again becomes suspect as it effects both Banks or both upstream O2 sensors might be bad but mileage is low & they should throw codes. Rich on both Banks means both Cats likely OK. I would start by cleaning the MAF.

Good luck!

Javvy

thankx glyn, will clean the MAF and then see if the code repop.....now off to search a DIY for cleaning the MAF...will report back......dont mind changing the sensors as they are not that expensive.....juts need to know what part number and how to DIY....search begins now...

javvy

Glyn M Ruck

I hate spending money without diagnosing the problem but this one is taking us around in circles.

Javvy

Hi Glyn,

Cleaned the MAF but the check engine light still exists and the MPG is taking a dump......from my reserach I found out there are 4 O2 sensors in this car, left/right upstream seams to be swappable, and left/right downstream different types i guess because of the long and short harness.......

Now I dont mind swapping outr the old sensors with new ones.....so from what you are saying I should replace the old upstream sensors both right and left side...correct???

Please advise..

Javvy

Javvy

Glyn M Ruck

Sorry Javvy - missed this one. If you are adamant that the air cleaner is down tight over the MAF we are back to a MAF misbehaving or upstream O2 sensors. I'm puzzled as to why we are getting no other codes.

I hate spending money without proper diagnosis - but this is where the dealer has an advantage. They can throw parts at the problem

Your choice if you want to keep away from dealers. New MAF or new upstream O2 sensors at least. I frankly in the absense of further codes don't know which to do first. Flip a coin!

Javvy

thanks Glyn......after I cleaned the MAF I did not reset the check engine light, but after looking at he costs for the new upstream sensors my lazy a s s did the reset yesterday .....the check engine light has not popped back on...I am keeping my fingures crossed and hope that it was the dirty MAF and not the O2 sensor.....

looking at the cost for a new MAF v/s New O2 sensor....I would say repace MAF first and then the O2 Sensor........

will keep you posted....thanks for the reply ....really appreciate it.

Javvy

Javvy

problem fixed, got it diagonised by my indy and he isolated the problem to the MAS sensor. Bought it from RMeuropean for $183, replaced reset and the egine is running smooth, got it inspected and it pased no problem. So the problem was with the MAS sensor being bad.

Thank you all for your help specially Glynn, always there for all of us.

Appreciate your help Glynn.

Javvy