I have a 2005 C230 Kompressor coupe with about 135,000 miles on it. This is the first time I have had any problems with the car. The car doesn't overheat, no leaks anywhere and in good shape. My problems started when the car wouldn't accelerate on the highway and the check engine light was on all the time. A shop that I trust said it is probably the mass air flow sensor. So I replaced the mass air flow sensor and both O2 sensors but the car still did not run very well (limp mode). I took it to the shop and they said the codes read the catalytic converter had to be replaced. Logic says that if the O2 sensors were bad, sending false data to the computer and/or the MAF sensor was bad, then fuel could have trashed the catalytic converter. So I replaced the catalytic converter. The battery happened to go bad, this was the original battery, so I put a new battery in it too. I saved a lot of money by doing all the work myself but this is getting to be an expensive project and I need to see it through. The check engine light is not on any longer. I bought a code reader and connected it. I saw the error codes from before I started the work. Before I started the car, I cleared the codes and wanted to start from scratch. It now says there are "no error codes found". The motor starts up fine and idles ok, but when I put it in gear and start down the road it is like there is little power. I take it out on the road and the car still acts like it doesn't want to move just like before I replaced the parts. My code reader is capable of displaying real time data, trending PID, saving and printing. So I left my code reader connected as I was driving. A lot of data and still no error codes come up, but I don't know how to decipher the information on the screen as the car is running. Except for the obvious readings like RPM, speed, and various temperatures, I really don't know what I am looking at but I saved it and ran PID trends. I still don't know what it means. I need help but I don't want to keep depositing $1000 into this car.