time to replace the catalytic converter
 

Hi Guys
I have to do some exhaust repairs on my 2000 Saturn SC1 -( manuals trans). It's a great car, 40 mpg in the summer, 35mpg winter.
I have to replace the flex joint attached to the down pipe. Unfortunately, It's a welded system. The down pipe, flex joint and cat are all one welded system. So when I do this I figure I will put a new Cat on. Is there a good cat for mileage? Is a performance or hi flow cat worth the money?
thanks

First, Do you live in a place where they check emissions?

They do make high flow cats. They don't always work as well as the stock ones.

No. I really don't want to do a cat delete either. If I delete the cat, the down stream O2 sensor will not operate correctly. I detest a perpetual check engine light.

any recommendations? Stock replacement of otherwise?

They sell just the flex piece that you can attach to your existing cat, or you can buy the whole setup with a new cat.
It's Walker 53325 I think for the flex piece and $59 at Rockauto.com Then you can use a universal cat for probably under $100 (I see universal Catco converters on Summit Racing for $70) (or $116 for the Walker Ultra cat at Rockauto)
They whole assembly is about $170 but only the California version shows in stock there (I think it's fine to use a Cal on a federal, just not the other way around if you lived in CA).
If all you need is the flex pipe I would just get it and not replace the converter unless it is actually bad.

Use a spark plug non fowler to cover the rear oxygen sensor.
It will trick the rear sensor into reading the exhaust leaner than it really is.
No check engine light.