rholbrook

I have had my E550 for a year and a half. The car drove like a dream up until a month ago. I have 40,000 miles on the car. Last month the car seems to have lost 100 horsepower. The throttle is sluggish and the car wants to shift sooner than it used to. It goes through the gears quickly at low speeds. It's like a tank. I don't think its the grandpa mode I think it is something else. When I punch it there is a dull response almost like the car is gasping for air. It's like a valve or something is not opening correctly and the car is not breathing properly. The car seems to want to slow down and downshift faster than normal when I take the foot off the pedal. If I gas it hard it takes more pressure on the pedal than it used to to get it to take off like a rocket. As soon as I release the pedal the car is slowing down and downshifting differently than before. Before the car would continue to upshift and ask for more gas. Now it wants to slow down. When I'm going down a hill the downshift to a lower gear is more pronounced and the car wants to slow down more quickly. Overall the car is more sluggish. Coming home tonight I think I heard an engine knock.

I took the car to the dealer and they plugged it into the computer and found no error messages for the engine and transmission. I was disappointed because I know how the car can perform and I swear it is down 100 horses and feels like it inhaled a large bug in the intake manifold and it can't breathe. I was hoping some breather valve (the car is a California based) or emission control valve or tube was blocked or leaking. The dealer also did a visual inspection and did not see any problems.

Has anyone else had a similar problem?
Thanks everyone

Airmousam

So they did a visual and attempted to pull codes....both showed nothing....so have they been for a ride with you to experience the issue real time? Seems the next logical step. Good luck!!

homeofstone

It has symptoms very much like a clogged or internal break in the catalytic converter.