Can exaust leak (loss of compression) slow down car?

[skipinschool]

Hey guys.. today, after i replaced the mass airflow sensor and reset my car, i noticed a deep rumble when i pressed the gas... i turns out it is an exhaust leak right on the left CAT. I could feel exaust fumes coming out of this flat hole. I dont think its a big hole, but theres a big difference in the way my car sounds and runs! It was louder before i replaced the airflow sensor, but that was because there was a higher oxygen/air mixture from the faulty sensor. Im also thinking that the car might be running a little slower because it has a good sensor (the bad one let more gas in with more oxygen, therefore possibly more power; but the check engine light was on, and thats what i didnt like [:(!] ) Anyways.... i already have a CAT to replace it with, but i just wanted to know, could that be the problem??

Thanks for the help!!!

P.S. if anybody needs parts to the E-class (w210) M-Class (w163 i think) or the S-class 93-99. than call me up!! got lots of replacement parts since i manage and partially own a salvage yard. My name is dominik... Call me up. My number is on my signature [:D]

[mjhawkins2346]

There could be a few things out of balance.

A hole in the CAT tells me you had burn through from overheating. Mixture out of balance is one thing that could cause this.

How are your O2 sensors? They could be bad too, and not too expensive ( compared to the MAS )

I would run a test of your failure codes as a great start.

If the CAT has a hole, it is no longer functioning well (if at all) so the downstream O2 sensor should be throwing codes right and left.

If it was me I would minimize any running of the engine until it can get checked out to avoid doing further damage.

Just my read on it. Good luck.

[sosh]

An exhaust leak is unlikely to cause low compression. Per the previous poster, the CAT could be burned thru however, its more likely that it is cracked or punctured by some damage. Remember, CATs are a consumable item and they do not last forever.

[skipinschool]

hey.. thanks for the info, i have some CAT's for this car so i'll have my mechanic swap them out along with the O2 sensor. Also, i am not getting any codes from a faulty CAT because the hole is behind the CAT. Maybe when i do replace the CAT, that will also stop that horrible "grinding" sound near the CAT when i floor it.... (at least thats what the mechanic said). But yea, once agian.... thanks for the help... i know theres a hole there and its getting replaced today, hopefully ill feel a difference [:D]

P.S. i have LOTS of w210 parts for our E-Classes... if anybody needs anything, let me know! My name is Dominik! [;)]