01 Impala-High rpm shift/Tran slip

[jjixsaw]

Hey guys - Just needing some advice about what might be going on... I believe I have a line-up of the suspects that could be causing this particular problem; but I know that there is a LOT of smarts in here that I need to tap before I start trying to fix the problem.

I've got an 01 Impala LS 3.4 automatic. apx. 81,000 miles

Here is the problem:

"Generally" - when the car is cold (i.e. just started) it is really hard to accelerate from first gear, and tends to "slip" into 2 and so on. This typically only happens when the car is running cold... I've noticed that it takes quiet a bit of RPM for it to shift to the next gear. Lately I've noticed it also starting to do the same thing when the car is at operating temp; albeit nowhere as bad as when its cold.
I've also noticed that if I don't really step on the gas to accelerate really hard it doesn't do this (even when its cold). Generally only does it when I step on it pretty hard - but this is DEFINITELLY not normal.

I tried to kind of read up on this to see if this might have already been covered by another thread... I did see a few threads that might seem to be close to the same symptoms that I have. The two things I came up with were: clogged catalytic converter (what seems to be most popular) and/or the PCS in my tranny is starting to go bad. Is there a way I can go somewhere to have them connect to the car and check to see if it is the Cat Conv.??? Would having a clogged Cat. Conv. throw error codes?

-I know that for the 01-02 models they upped the warranty on the cats to 120,000... Anyone else have any more input on this?

[phewop118]

Get your transmission scanned for codes. It sounds like your valve body is dying.

[SpinnerCee]

An exhaust back-pressure test will determine if there is a catalytic converter issue -- Air is pumped into the exhaust through the O2 sensor fitting, and the pressure is read. A good shop can and will perform this test cheaper than the dealer.

The dealer should replace the cat(s) for free if they're bad -- since they're an emissions-critical item, they are lifetime warranted.