I have a 97 Honda Accord manual transmission with about 150,000 miles. It’s been a great car with not many problems around town. The problem is when we take it on a road trip, after about 5-6 hours of driving. It starts to run rough, like cylinder is randomly misfiring, or it’s about to stall, at all speeds including highway speeds. If you stop and are in neutral, the idle drops really low and most often stalls. Again this only is after driving for 5-6 hours. About to take another long road trip for Christmas and was wanting to take it to a mechanic but wanted to see if anyone had any thoughts first. Thanks!
Check engine light on? If not maybe a fuel pressure problem?