Lately I've been having problems with shifting. I have an automatic. When it shifts into 4th (I think) the rpms go to almost 4k. If I let off the gas it will shift. This also happens when I'm going about 40 or so. It's done that for about 5 months, but getting to 30 just started. I really don't want to think the tranny is bad. I have checked the fluid and it's a decent color, not burnt. I also smell a rotten egg smell from the exhaust. I've had the exhaust manifold gaskets replaced but the smell is still there. This leads me to think that the catalytic converter is plugged. I also don't have much power. Any help greatly appreciated.
This weekend I'm gonna take down the pan and replace the fluid and filter to see if that helps.