I drive a 12-year-old Honda CRV with 185K miles on it.
Recently, I had the car in the shop to fix an oil leak in the engine. I also had the catalytic converter replaced, since its connection point was badly rusted. Since I got the car back, I have been experiencing intermittent trouble accelerating the engine when I first start up in the morning. The engine idle sounds normal at first, but when I take my foot off the brake and put it on the accelerator, nothing happens for several seconds. Eventually, the engine seems to kick in and accelerates almost normally, though a bit more slowly than it used to.
The problem seems better if I make sure to rev the engine loudly when I first start it up and worse if the weather is damp or it has been raining since I last drove. After a few minutes of driving, the problem has always gone away so far, but it is nerve-wracking to pull up to an intersection, stop, and then have trouble accelerating to get through it, especially when there is oncoming traffic on the cross street.
Does this sound like a problem with the idling, or am I experiencing the beginning of transmission trouble, or could it be something else? Is it likely to get worse over time?
Many thanks for any suggestions,