I have a 2003 LS with the 3.4. If I'm at a stop and step on the gas too hard to take off the car revs up, but doesn't move. Then it kicks really hard and takes off. is this normal? I've never had a car do that before. The transmission shifts fine and doesn't seem to have any otehr problems. Anyone ever heard of this?

 

Moved your thread to the appropriate section.

It could very well just be a solenoid, or it could even be a clogging cat.

 

Thanks for taking care of moving the thread. I'm reasonably new to all this. LOL. Anyway, it may very well be the cat, because I've been getting the dreaded P0420 code and the check engine light keeps coming on.

 

Then that could very well be the problem. I would honestly start with getting that fixed (your local dealership may fix it for free) If they don't do it for free I wouldn't get it done by them as it could be very expensive.

But you should call, or drop by a place and ask them if they could check to see if your car falls under the extended cat warranty. Remember to have the VIN# available.

 

Thanks for the advice. I checked with a dealership and they said that the policy change on the cats is just for 2001 and 2002 Montes. So it looks like I'll be changing it myself. That being said, I know that it's probably been asked a million times on the forum, but what cat would you guys reccomend? I was thinking about just getting a Magnaflow cat, but I've never had to buy a cat before, so I'm not sure what to look for.

 

When needing a new Cat last year, I went the route of installing a whole new downpipe w/Magnaflow Cat from ZZ Performance. Not only do you get the easier breathing Cat, but you eliminate the U-Bend in the stock downpipe as well.

It's an easy job - if you can free all four of the bolts. I had two bolts up top that I couldn't break free. A local exhaust shop did the job for me for about $40.

 

Well, I took the car in to the shop this morning to have the cat checked. The shop said the cat is fine. So now I'm not sur what to try next for the P0420 code. Anyone have any suggestions?

 

If you have the P0420 than the cat is bad.

Take it to an exhaust shop and have them test it properly

 

I doubt the transmission slip in 1st gear has anything to do with the exhaust.

 

You would be amazed how much a clogged cat can ruin the performance and feeling of the car.