I have a 2002 Monte Carlo SS with 130,000 miles on her.

1. About a month ago my car was having trouble shifting out of first when it was cold. I hadn't had a transmission flush done on it in the time I've owned it so I knew it needed it. The flush and filter seemed to have fixed the cold hard shift out of first, but now its shifting hard in 1st, 2nd, and 3rd when its warm (in stop and go traffic).

2. It is also having issues starting when its warm. The RPMs flutter as if its going to stall, but doesn't.

3. AND The RPMs are not always consistent while sitting still whether it be in park, or drive.

As I mentioned, I had the transmission flush done and filter changed. I've also had a tune up including new spark plugs and filters, and a new mass air flow sensor.

I have researched similar stories on here but none of them seem to fit my issues precisely. Any suggestions would be greatly appreciated!

 

Clogged Cat?

 

I had it replaced a little over a year ago... Could it be clogged already? I have had an exhaust leak ever since I had it replaced... Do you think that could be related?

 

Dunno if it could be clogged already.

You mentioned a lot of the tune-up stuff, but forgot O2 sensors?

Also, if the RPMs are fluctuating and hard start when warm and the MAF was changed, check out the IAC Valve and clean/replace if needed

 

Thank you! I will check out those options.