Gondon

So I went in last week for the 8yrs/80k CAT replacement. They found the right cat was bad so they changed it and I got my car back .1 hr later of driving, the noise was back so this week I was in for the same service now it was the left cat...LOL no chance that it just went out, it was prob bad from the start and they got cheap..and decided to do the only right one.

So I pick up my car now both cats are fresh left and right. But the car performance feels sluggish the shifting and the deceleration as well as acceleration are tottally different plus I had my mirrors bend down when I would park and reverse..Now its gone..Plus there is now a slight fart noise from my car like a ricer coming from the cats... wtf

I did a 0-60 run and the numbers appeared the same as always.. but the car feels tottaly different, I cant xplain it. It used to feel light and free and now heavier.

Satan

They probably unplugged the battery or reflashed your ecu. Your car will relearn your driving habits. The mirrors you have to change in the dash.

sessayan

My car felt diffrent after they replaced the cats as well. Felt sluggish and slower. After a few weeks, it seemed to get back to normal even though it still fells a hair slower then prior to the cat replacement.

Thugs Bunny

Guessing here but I would presume an old cat would allow greater exhaust flow, thus better performance than a new more restrictive cat.

Gondon

Just drove 100 miles everything is out of sync, Feels like suspension is terrible i feel all the bumps,unsmooth, power is retarded I Push 50% of the pedal and recieve near WOT results lol. 60-100 acceleration seems slower..I cant confirm yet..Ill run my dynolicious program tommorow or whenever I get on an OPEN ROAD.

Im ready to throw this out and trade it in for the 55 or 600.

WTF did they do to my baby

DrJfrmLA

Don't know whether the earlier W220s are the same as my '04, but my tech told me that there is fuzzy logic all over the driving systems in the car--suspension, brake response, transmission controller, throttle response, and on and on. The car learns the way you drive over time. A heavy foot gets you higher-rev shift points, quicker throttle tip-in, harder shifts, a little stiffer ride....If the ECU is flashed or the battery disconnected, everything defaults to the factory settings and the car has to relearn everything. This is true of a lot of new-design cars; Lexus sedans and Toyota SUVs are that way. The car can feel dramatically different for a while until it relearns how you drive.

BTW, this is pretty creepy to me, but that's what the tech swears happens.