I've been struggling with this problem for a year now since last summer, however, it only shows up in the summer time when its really hot here in Vegas.

When I drive my car a lot in the heat, I'd estimate 25-40 miles, the throttle will stop responding correctly and the rpms jump around a lot and it seems like its struggling to stay on, and then the engine just cuts out. If I immediately try to start it, it won't start, and if it does the problem just reoccurs.

However, if I let it sit for about 30 minutes, it turns right back on and I can drive it for another 25-40 miles before it does the same thing. Any idea what this might be? It seems like something is overheating but I can't figure it out. Maybe sparklug wires? fuel pump?

also, I do have a CEL on. I had it checked last summer and I believe it was a CAT code or an O2 sensor code, don't know if that's relevant. And my engine also seems to have a light hissing noise which I believe might be a vacuum leak or something, if that helps.