In my last thread I was stuck in SMOG limbo with oxygen sensor and heater not ready. I learned I needed to remove my Eurocharged tune and did so. Things looked up as the downstream oxygen sensors became active on my first drive but now that I have finally taken it for a long drive I got a CEL and 10 new codes. Looking for your collective wisdom on what to do again. I already replaced all 4 oxygen sensors. This half hour drive is only the second drive since I took off the EC tune and I never reset anything. Maybe the car is freaking out after finding its downstream sensors for the first time in several years? It can't suddenly have this many problems with no actual noticable problems in the cars performance and function can it? Ive read about changing the air filter to K&N causing problems and I recall replacing the filters years ago but I don't recall removing the carbon filters, I'll have to check those tonight. Also, all these faults showed up under my iCarsoft engine diagnostics menus but I still show no faults under OBDII diagnostics and only the catalyltic shows as not ready now.

Motor Electronics:
374a - No info
0745 - Mixture bank 1 too lean
0749 - Mixture bank 2 too lean
2091 - Mixture bank 1 too lean at idle
2095 - Mixture bank 2 too lean at idle

FSCU - Left Fuel Pump:
U0100 - Communication with ECU malfunctioning
P0030 - Implausible signals from component N3/10 (ME-SFI[ME]) control unit

ESP:
5001 - Control Unit N30/4 (ESP Control Unit). Internal Fault
6108 - No CAN message was received from control unit ECM

Central Gateway:
U102700 - Chassis CAN bus off fault

Driver Side SAM:
B179715 - Left standing light 2 has malfunction. Short circuit to positive or open circuit

I'd leave this to the diagnostics experts but what I would do if it were me. clear all codes, flash original file using handheld again, clear faults. drive a few cycles and see if they'll return.

what are the full list of mods done to your car?

I only did the EC tune, now removed and set back to stock, and I may have put k&n filters in years ago. Can't remember. Nothing else.

i believe when you reflash using a dimsport handheld it does in fact reset fuel adaptations as well. I would look to reset those if you are not using a dimsport handheld. if fuel adaptations haven't been reset, it could be why you're seeing the lean errors.

Pull battery both terminals overnight. Drive car normally there after until everything sets. Dimsport causes issues since it interrupts the CANbus. Should be good to go after

I am not using Dimsport. I have the MyGenius hand held that came with the Eurocharged tune years ago. They had my original factory tune on it which I flashed back. I will still try pulling the battery tonight. Could my factory tune file from 2012 cause problems with any updates Mercedes may have performed during services over the years?
EDIT: Ok I can Google. Dimsport and MyGenius are the same thing.

mygenius is dimsport

Update: For my first attempt I reset all codes using the handheld so I could log my long commute home from work. After getting back to work the next morning the CEL came back on with all four "too lean" codes 0745, 0749, 2091, 2095. All of the other CAN bus codes have not come back and all of the SMOG readiness stuff now shows ready which is awesome.

It looks like the lean issue may be a real problem though. I could either try the battery disconnect tonight or begin troubleshooting those codes which around here sound like anything from removed charcoal filters to a bad intake manifold gasket. What would you do?

Well if they are real which it sounds like they may be, then you go looking for a vacuum leak and most likely suspect is intake gasket, easiest thing to do is spray around the intake manifold with something and listen for changes in RPM when idling, spray carb cleaner is what most people use. Lean means after the MAF's more air is being introduced, so the filters/charcoal should not make a difference as a leak in the airbox will still be detected by the MAF, check the clamps behind the airbox and then check the intake for leaks at the gaskets or sometimes the intakes rot out crack and leak in the bottom or by the throttle bodies.

maybe your PCV valve is bad causing excess crankcase pressure to leak into the intake. carb cleaner trick as mentioned will help isolate any leakages. pretty rare to see both banks showing lean codes though. i believe if it was an intake gasket its usually just one side that leaks, not both. spraying carb cleaner while the engine is on will help isolate that issue.

I will see what I can take apart tonight and hunt for leaks. I have break cleaner, close enough? Actually, carb cleaner is probably closer to gasoline and better if sucked into the engine. I'll get some.

UPDATE:
I removed and inspected the air boxes and the Y tube at the back and they don't have any cracks. The air filters look pretty dirty and need replacement. I then started the engine and sprayed carb cleaner around the manifold. That stuff boils off like crazy. When spraying around the front left and right of the manifold the engine bogs down by about 50ish RPMs as read by my iCarsoft and you can hear it too. Spraying on the left side causes a crackling sound which I think is just the cleaner boiling off but no bog down. Spraying along the right side doesn't really do anything. I then tightened the bolts by an eighth to a quarter turn and spraying yielded the same results.

So is that what I was looking for, a subtle loss of rpm when spraying? Does that mean I should just change the gasket and bolts? Maybe I should change the PCV valve while I'm down there. Anything else?

Not sure about your leak but if you’re yanking the manifold, might as well go all-in and throw some 82mm TBs in there!

Yes gaskets, all bolts and the PCV since it's 100x easier when the IM is off the vehicle.

Clean everything as well. If you don't have a catch can (now's the time) it will be full of oil.

Good advice about the PCV and it isn't real expensive. Only other thing to maybe think about would be injectors if you wanted but they don't require the intake off, just is a tiny bit easier when you have it off as everything is out of the way. If you do decide to do injectors, there is a thread around here on the non amg ones to use as they are only 28 bucks and they work like a top and seem to be identical except no amg log and a lot cheaper https://www.rmeuropean.com/Products/...023-MFG14.aspx

At least maybe inspect them when you have the intake off and see if they have any build up on the tips.

Thanks for the suggestions! I just need to get this damn beast to pass smog so I really don't want to add any more variables like the catch can or TBs at the moment, or add more money. I'll have to read about the TBs and how larger ones would change anything or effect my V4 Eurocharged tune when I put it back on. The catch can sounds like a good idea, I'll have to see how much oil is in that manifold. Parts are coming 1 state over via ground so I'll be back after the gaskets and PCV is installed, hopefully to report no more 0745 0749 2091 2095 lean errors. Thanks!

Good luck OP. I had a CEL and only a week to smog check. I reset the light and went to the smog station just as soon as my monitors were ready. I passed, but the CEL came on literally right as I was pulling out of the smog garage, lol. I've fixed it since.

lmk if you want to sell your old PCV valve.

You want a 2009 PCV valve with 108k miles on it? They are only like $100 new.

He wants to cut the ends off to use for a catch can. I can help you pass smog but you need an obd reader that shows mode 6 data. In there you will see what is causing the codes and what bank.

I use obdlink

Oh cool. All I have is an iCarsoft i980 for Mercedes. It definitely has a lot of information available but my search on mode 6 just now makes me think it doesn't have that.

well yes...I want to use my working PCV as well as another for flow back for my catch can. flow back doesn't need to be perfectly working because it's for flowback.

Dnot worry about those weird codes it's from the canbus being freaked out.

Your rear o2s play a roll on your front o2s and will cause havoc. I spent months messing with my car to get it to pass smog being catless and learned alot.

I would change your rear o2 sensor (I know sounds crazy) but I need to see the mode 6 data on them. The car uses them to adjust its af open loop and if they are clogged up its thinking the af is lean.

You need to get the rear o2s to read between 5500 and 6300 in mode 6 data. I was using spacers with no cats and if I got those values under 5000 or above 6500 the car would throw front o2 codes of being to lean or to rich and after running a combo of spacers I have my car reading like stock and passing smog without cats.

OK I will look for those values and see if I have them. The first thing I did after the dealer told me I needed to replace all 4 oxygen sensors for $2200 was go home and replace them all myself. Then I realized, thanks to people here, that my tune was shutting off the rear two so I removed that and they came on and all SMOG parameters went ready and the only errors left were the 4 showing bank 1 and 2 running lean. That led me to do the intake manifold leak test suggested here with carb cleaner and I found the front left and right of the manifold causing RPM drops with carb cleaner. I have new intake manifold gaskets, PCV valve, bolts and air filters arriving today so that will be my next attempt. Will report back. Thanks!

UPDATE:
So I put the new gaskets, PCV and air filters in today and went for a 45 minute drive. Unfortunately, I cleared the codes under my readers diagnostic area but forgot to go into the OBDII smog area and clear those codes. Although SMOG items set "ready" by the time I was back there were two permanent codes for bank 1 lean in the OBDII area. There were no codes in the engine diagnostics area and the CEL wasn't on but I had to clear the codes in the OBDII SMOG section now and start over. I'll probably go for another drive tonight after the car cools down. I'm pretty worried though that the codes there were new and the problem is not fixed by what I replaced.

UPDATE 2: Tried the carb cleaner again and still got slight RPM change in the front. There was some corrosion on the bottom tray, probably more inside had I removed the back tube clamp and taken it apart. Think I'm going to get some JB Weld, take it all apart next time, seal up any corrosion and see if that does it. Take a look at the picture below. The only outside corrosion I saw was a tiny little line of corrosion starting in the front middle of the bottom of the intake.