2001 Regal 3800 LS will not down Shift going up hills when on cruise

[Weinerdad]

The problem started last week while returning from Yakima and the speed fell from 70 to 30 before I took it off cruise. I took it to a shop this week. They said the exhaust back pressure was 3.5 psi and I needed a new catalytic converter that they would install for $1500. I ran away! The car seems to work fine if I control the speed manually. Does anyone know the "normal" back pressure for this engine? What about other possible causes for the problem? What I know about cars is that if they stop working, they are broken. Weinerdad (I have 5 dachshunds)

 

[HotZ28]

Anything over 2-psi indicates a problem with the exhaust system. You can get a new cat & down pipe for $168.79 and bolt it on yourself. If you do not have jacks, or ramps, take it somewhere and have them install it. They should not charge more than $50.00 to do it (30-min job). Click Here for the best solution, unless you are in Cali. EASTERN CATALYTIC Part # 50321 You could have other problems, but this will be a start.