Catalytic Converter Problems

Why does My Oldsmobile Alero 3400 V6 Chug at 35 MPH
When you go 35 or higher like it not getting gas or something . It has got worse since i changed spark plugs and fuel filter.

My Buick Lesabre has code P0420
Mass airflow sensor and 02 replaced and then had a new catalytic converter installed 2 weeks later. Car runs fine but now I have the check engine light coming on several months later.

No Power, Engine Runs Bad
I have a Pontiac Grand Prix 3800. It doesn't have any get up and go. When I floor it, it bogs right down. I changed the fuel filter but it made it worse. I had it put on a scope at two different repair shops.

2002 Pontiac Grand Am SES P0300 P0404
Replaced fuel filter, fuel pressure regulator,plugs, plug wires, air filter, and EGR valve. The EGR valve was replaced after the service engine soon light came on. Catalytic converter damaged? All other repairs were made before the light came on but after symptoms started to appear.

Question: what is the average cost of replacing a catalytic converter and then the battery in a 1993 mini van.
 Answer: A lot depends on the make, model and year vehicle. But a rough idea is about $125 plus labor for a cheaper after market converter, up to $600 for a factory part. Batteries range from $75 plus labor to $135.

my Ford Crown Victoria year of 2003 always loses power at a 35mph speed when going up a hill and after going down a hill or on a flat highway it gets back to a speed of up to 70mph.
 Add a bottle of Gumout Fuel Cleaner on your next two fill up. Guarantee the check engine light will go out.