cat converter

the cat converter on my car broke
the pipe going to the front of the engine separated from the cat. converter.
the car really roared and there was a loss of performance.
could barely go 30 mph.
Is that normal for the loss of power.
I have to change the cat converter(itwas temporarly repaired with a weld from a coathanger) .
Before i change it i would like to know if thats normal for the loss of power.
It is a single outlet exhaust.

It sounds like the cat was partially plugged and when it broke the exhaust could leave the car more easily. If you want more performance you may want to get a high flow cat. They cost a little more but the performance is worth the money.

Thanks GTP Dad
After the temporary weld the performance was ok,
If the exhaust could leave more easily would that cause a lack of performance.The pipe was disconnected not at the back of the cat but in front going in the direction of the exhaust manifold.
Before the weld the car could only go up to 30mph
my previous post was not clear.

I am sorry. I misread your post. Usually there shouldn't be a loss of performance but when the back pressure is too low that can cause the engine to perform poorly. It also fools the O2 sensor and it may run lean or rich depending on where the sensor is located.

GTP Dad
the sensor is located on the exhaust manifold 18 inches from the cat approx.
its a 1988 pontiac bonneville
do you believe its normal for the car to go only 30mph when the pipe was disconnected or i may have another problem with the car.
the cat will probably cost 200 to fix but if there is another problem that could cause complications.
To find a problem takes time and is expensive.
If theres another problem ill probably take out the cat and put a pipe in between.The car is an 1988 and 2 weeks ago i changed the 2 back brakelines and the cost was 260.
Your help would be appreciated.

It is not normal but if repairing the hold before the cat made the problem go away then I would not worry about it any further. Do you have a check engine light? If the light is off then the car is running properly and there is no need for concern. If the light is on then you need to find an OBD I scanner and check the problem otherwise just keep on driving.

if you can only get 30 mph out of your car whether the cat is on or not on, you have a problem the same thing happened to my 89 olds eighty eight which is essentally the same motor and despite being louder than hell and losing power slightly there was absolutely no problem maintaining hiway speeds and beyond are you sure your car was running on all cylinders?