Running with no cat=big difference?
 

Hello, I just got my 500SEL back from the shop. Apparently the catalytic converter was at fault and since most of the exhaust system was pieceed together from universal parts, they replaced the whole thing.
Anyway my question is: does running without a cat make a big difference? The car is incredibly slower now than before and I'm wondering if it's solely because of it having a cat now.

I had a european 500 with a running problem one time ( slow doggy acceleration ) checked the c/o etc . Well ended doing a backpressure test and it was so small of a cat was installed on the car. Had a 560 cat put on and the car ran excellent. Something to think about.

Well this is the OEM complete exhaust system he put on, I guess I didn't know these 500SEL's were slower because there was no catalytic converter.

This is a 126 body european 500 right ? If it is they run probably better than any v8 , even a 560 when tuned properly. We had one that would outrun all of our customers 126 body cars , whether it was a 420 or 560. The europeans seem to run faster and have better acceleration than the regular american versions.

Sorry I should have said that earlier, it's a us spec one. But I do understand that the euro spec one is considerably more powerful. I can get used to it though. Hopefully at least I'll be getting better gas mileage.

You should definitely replace the catalytic converter. If you think it's slow now, just wait until it fails its next emissions test and manages zero MPH...

Ron
German Star

Oh no defintely. It was replaced once I found out that I was running without one. I had no idea. The mechanic then inspected it and saw that it was working properly so it was replaced.
Anyway I was just trying to see if the loss in performance is due to it now running the way it should be. I guess that's it.
Talk about failing the emissions test, I failed it three times until the real problem was realized.

to answer your question, cars run faster without any cats
attached to it.

Alright, thanks. :)