I have a 2003 cts with about 75k on it, recently the shit has hit the fan and it is just one thing after another going wrong. Most recently i was getting on the interstate and gave it some gas and all of a sudden on my navi screen it said service engine soon, and cut power to protect engine? at first i thought it was the timing belt, i got out looked under the hood, everything intact and good. Then naturaly i looked under the car to see if any fluids are pouring out, nothing. So i cranked the car and it seem to be fine, but when i slow down it feel as if the transmission is slamming in gear. The transmission indicator in the car reads my fluid is 100%. What could be causing this? I had my mechanic look at it and he says the mass air sensor is throwing a code, could this be the problem?

Yes, this COULD definately be the problem... The TCM uses inputs from many different things, including the mass airflow sensor (MAF sensor) to calculate shift points. Try cleaning the sensor first with some mass airfow sensor cleaner from autozone or other parts store... When you're standing in front of your car (in the US) looking at your engine bay, the sensor is located a couple inches left of your air filter box. It's fairly easy to remove with the right tools (two star-pattern screws hold it in). Remove it, and clean it using the direction on the cleaner can. If this doesn't work, you'll need a new sensor... Hope this helps...

Press F1 AND F3 together on dic and get the codes.
Sounds like something to do with throttle body.

Thanks a lot you guys, ill clean the MAF out tonight and let you all know if it fixes the problem. Also i will get the codes and list them tomorrow. thanks again

also what are the F1 and F3 buttons? i have a navi unit and no clue where those buttons are...

Its the F1 and F6 buttons, actually. If you have a NAV, you dont have these buttons.

Here's a link that might be able to help you get to the codes with a nav unit...

http://www.cadillacfaq.com/faq/answers/codes.html

Hope this helps...

Well that seemed to help by cleaning the mass air, but the whole problem was i had a cam shaft sensor replaced, well the guy that replaced it for me failed to clear the code, so the computer sent the code again and that in turn through other code which cause my problem. You have got to love the complicated cts! Thanks again for all yoru help

Well that seemed to help by cleaning the mass air, but the whole problem was i had a cam shaft sensor replaced, well the guy that replaced it for me failed to clear the code, so the computer sent the code again and that in turn through other code which cause my problem. You have got to love the complicated cts! Thanks again for all yoru helpComplicated is the name of the game now! If youre buying a luxury car nowadays, expect a dedication to complication. I even think Audi's unwritten slogan is 'why make something with 1 moving part when it could have 15 moving parts'