I got a 98 1500 4x4 5.9L with auto tranny. The problem I have is that after the engine begins to warm up the truck stalls in reverse only. You can put the truck in park, drive, and neutral and you won't have any problems. You can drive it down the road or let it idle and it's fine. You put it in reverse and the engine rpm's fluctuate and the motor stalls, this only happens in reverse. The tranny is brand new it only has 4000 miles on it and I just got done doing a tune up after I ran into another problem with it stalling and not running correctly. I had to replace the o2 downstream sensor since it kicked a code. Now I have this stalling issue and I don't have any codes being kicked out. So where should I start looking to solve the problem of stalling in reverse????

 

Only in reverse?? That's just odd.

Try cleaning the throttle body/IAC motor/passages first. See if that helps.

Have you fixed your plenum yet?

Welcome to DF.

 

Yep, only in reverse. All the other gears are fine and it runs down the road like normal, no hesitation or missing. I just got the truck 2 months ago and right off the bat had to replace the tranny after 3000 miles, they didn't have the aux. cooler hooked up so I fried the tranny towing a mini-van. Can you explain the plenum deal that you're talking about? I saw in another forum that they said to check the egr for the stalling issue.