Help! 95 Ram Misfires Only On Long Road Trips

Here's One For All You Diagnostic Detectives. My '95 Ram, 5.9l, 1500, Runs Great Around Town. But, On Long Road Trips, After About 10-12 Hours At Hwy Speeds, It Suddenly Starts Missing Badly, Loses Power But Will Idle. After About 5-10 Minutes On The Side Of The Road, It Will Fire Up Again And Run Normally. It Started Doing This Wierdness On A Trip I Took Last Year And Only Did It Once. It Ran Fine The Rest Of The Trip. On My Last 2 Trips, It Has Gotten Worse. Once It Starts This Problem, It Will Only Run For A Few Miles Each Time Before Acting Up Again. However, After Sitting Overnight, It Fired Up And Ran Fine All The Way Home, About 3 Hrs.

I Have Taken This Truck To The Dodge Dealer And They Couldn't Find The Problem. No Computer Code. Nothing. Checked Everything.

I think your cat converter is fucked but it's just not throwing a code.

I've had that problem before on a trip back from TX to SC. Would run perfectly fine for about 50 miles after I stopped for gas then wouldn't let me get above 70 until I stopped again. Took it in and Dodge said they couldn't find anything wrong. 20 some thousand miles later, including a trip from SC to AK with legs lasting upwards of 30 hours (55-60mph), I have yet to have that problem again. Not sure if Dodge messed with something and didn't tell me or I just had to keep it above 70+ for multiple hours. Since my trip from TX to SC I haven't had my truck over 70+ for anytime over 2 hours. I know it's no help, but hope you feel a little better that you're not the only one. Maybe it's the cat, but I've passed my IM test twice since it's happened.

go2tex , my 97 1500 slt is doing the same thing but it doesn't take multi hours of driving.it is a pain because i need reliable transportation. i have been told its the fuel pump, filter. cat.map, even halleffect.. i have not change anything out yet, would kinda like to replace the problem not everything under the hood. please post if you have any luck

LTJGworth had a similar problem, it was his fuel pump. Look under "My truck is definitely cursed"

Yep I sure did, my fuel pump was bad. It would suddenly loose power and start missing. Would idle poorly, but had no throttle response. Sometimes the truck would go for a long while befor eit would start to do this. Changed the fuel pump with one from AutoZone and have put well over 400 miles on it since I put it on and have had no problems. It's been on for a little over 2 days.