kidjnco23

Check engine light came on so I scanned it and it came up as bank 1 lean and bank 2 lean I have str8 pipes for the secondary's! Brought it to Mercedes today and they didn't have any loaners so I have to go back they want me to leave it, anyone ever have these codes or any ideas as to what it might be?

_AMG_

Highly unlikely the 2ndary cat delete will cause this.
What mods do you have on the car besides 2ndary cat delete?

kidjnco23

That is it no tune or anything just the straight pipes!

_AMG_

Could be a loose intake manifold gasket.
You don't have K&N filters, correct?

kidjnco23

Nope no k&n filters! And also when I brought it in I had mentioned to the steamers ip that only when it's cold out and I'm driving the headlights turn off and on, I have hid's in the fogs and they didn't wanna touch that because of it!

_AMG_

Your headlights turn on and off by themselves in the middle of driving???

kidjnco23

Yeah it's so weird it happened a couple times last year but I thought it was because I had aftermarket hid's in the headlights, so I put the originals back in and it was fine during the summer. Recently we had a couple of chilly nights in NY and they started doing it again, this is so weird because it only does it when it's cold out. The stelership says it's because I have Hid's in the fogs but I beg to differ!

_AMG_

That's very dangerous especially at night, I would have it fixed asap.

The only reason I would understand why they wouldn't work on it is if the headlights are directly connected with the fog lights.
Which doesn't seem like the case here. Have you tried going to another dealership?

kidjnco23

No I'm Gunna try this weekend see what they say, but I really doubt it's from the fogs!!

_AMG_

Ya, I doubt it too.
As far was the lean banks, I have a good feeling that its the intake manifold gaskets, the bolts get loose sometimes and just need some tightening.

kidjnco23

I'll check it out thanks Gunna bring it to another dealer over the weekend

loungn14

I had seen issues like that with the lights from fogs and a voltage issue. fwiw

good luck on the o2 issue..bad sensors?

kidjnco23

Nope not bad o2 sensors! You think it could be because of the fogs?

BK63amg

Sounds strange...can't imagine HID fogs would cause this. I've ben running HIDs in my fogs since I bought the car with nary an issue.

kidjnco23

Yea I know one dealer said it was because the load was too much and it was causing it but they only do it when it's cold out!

hhughes1

I definitely think you have two separate issues that both are affected by cold temperature. Now if you only get the lean bank codes at the same exact time the lights go on and off that would be interesting. Back to the lean issue, theses ECU's are hyper sensitive and it could be several issues working together. Slightly lower back pressure, cold dense air and possibly a leak ingesting unfiltered air could certainly combine to cause a lean situation that only appears during certain conditions. Good luck with the resolution and let us know how it turns out.

Merc63

My car has been giving me this code for a while now. I had it in to get it fixed. They replaced a valve on a canister for fuel tank fumes. Still the code came back.

I have the car there now and they found a leak on the intake manifold gasket, its a known problem with the M156, there is a SB for it. I talked to another member which had the same problem, they changed his intake gasket and used new bolts, he hasn't seen the CEL since.

The techs sprayed some brake cleaner around the intake gasket and got a rough idle at one spot, indicating a weak seal.

Its nothing major, its more to do with emissions, the ECU is really sensitive to these issues I am told.

kidjnco23

Good I'm hoping that's it!

jvanbrecht

With regards to your lights, mine were doing the exact same thing, turning off randomly (dash lights as well). It was the light switch itself, I had them replace it, problem has not returned.

A quick way to check is to turn the lights on, and then lightly wiggle the switch (kind of like what would happen on a bumpy harsh drive.. which cold would cause to some extent), if the lights flicker off and on, it is the switch.

kidjnco23

Well I wiggled the light switch but nothing so I don't know what it can be!

kidjnco23

Finally got the beast in the shop today and one of the service advisors says you know the check engine light could be because of the str8 pipes I go thanks dick! Let's just hope it not that hoping it's an intake gasket!

kmbeachums

mass air flow is defective.!!!!!!!!!!!!

hhughes1

Not unless both sensors failed at the same time........what are the odds of that?

kidjnco23

turns out my intake manifold was cracked on both sides, dont ask me how that happened all fixed and running strong wahoooo!!

Merc63

Common problem. Glad its fixed. I believe they use different bolts now.