Hey guys I have a 98 C280 sport. the check engine light was on when I bought it.(runs fine) the dealer said it was code P0410 for secondary air injection. they checked actual values and readings were good everything checks ok, erased code. Light came back on a couple weeks later, another German mechanic said it is probably an intermitent problem that causes the light to come on then goes away. Any Ideas before I open my wallet again so I can beware of snake oil salesmen. Thanks for the help .

 

I know several of these models, and I have the same one, build some carbon up and that causes the light to come on. The local independent Mercedes place tried to fix mine before I bought it but couldn't. However he said it wouldn't hurt anything. He tried snaking it out blowing it out, everything. Funny thing though since the last time they tried to fix it hasn't come on and that was about a year ago. So maybe they actually did fix it. I have only owned the car for about seven months. I knew the previous owner and she told me about it, as well as the MB mechanic that tried to fix it. This could be it or not. Just a thought.

 

I don't like CELs to remain on with the understanding that, "whatever it is it's not hurting anything and the car runs fine". Maybe that's just me. I'm wondering if you're CEL code is still PO410? Locally, I can have CEL's read for free at AutoZone; a car prts store. If it is indeed a PO410 (Secondary Air Injection), I'd find out more info about it. There are some tech heads on this forum, or you can try others (perhaps you are) Once I knew what was going on, I'd want to fix it. An air pump cost about $400, but I have no idea if that is the problem.
Good luck.

 

I don't know, all of this was before I got the car. I just knew about it before I bought it. The light is no longer effected ever since the last time they tried to remove the carbon and that was about ten months ago or more.

 

Run Shell 93 Octane for a couple of tankful. If it is available in your area. This gasoline is really good and cleamed out the carbon on my 79 450SLC and keeps my 99 C280 running like a clock. Also, when is the last time you changed your air cleaner?

 

Thanks for the info guys. 1st I dont think it is OK to run around with the light on just because it seems to run fine. I just got this car last month and took it to the shop first chance I could get, then a couple weeks later it came back on and I am planning on taking it in the next first chance I get. I just have a lot of schedule conflicts and my 3rd car is in the shop awaiting a new engine so that leaves my wife and I with only 1. I was just gathering info to help me better understand and deal with what the mechanic might say, or maybe offer him up some info I learned here. I will try that type of gas thanks.

Has anyone ever had a gas cap go bad???? the dealer loves to ask if the cap is on right, it seems to have a snug fit.

Just got the car so havent changed anything but will check, but the dealer who had it last changed the oil from inspecting the dipstick so I assume they changed the air filter. Good thought, thanks

 

No I wouldn't ride around with my check engine light on either. Don't know about that gas cap.