Hey guys
I was wondering if someone can lead me towards right direction on this matter
I have 2003 c320 4 Matic 145k 2 weeks ago started noticing that when your cruising and it shift from second to third gear it kind of hesitates (lack of power, almost running out of gas feel then it regains power) it was hard to notice at first but now it's becoming more noticeable
Most recent job was both axles and front brake pads
Since this issue I thought it would be from spark plugs so I changed all 12 of them (wasn't so easy) they were very old. That didn't fix the issue so I'm wondering is it transmission related? I ordered the dip stick to check the fluid level it should be here in few days.. Any other thoughts ? Does O2 sensor or maf cause this?

Thanks in advance

 

I am having the same issue except I have a C230. I had my sparks plugs changed and have a new MAF but the problem is persisting. When I redline the car it goes into a complete power loss mode.

I have a CEL which reads P0420 which is pointing to the catalytic converter. I am thinking that I need a new cat but have yet to get it inspected. If it isn't then I'm in trouble.

 

Was it the cat?