Hey guys, I have 98 ram 1500 5.2L 4wd. I think I have done everything I know to fix this problem but Im still having issues with the truck surging when I drive in town or highway. It has its good days and bad. I've replace the tps sensor, the plenum intake gasket, Plugs, air filter, what else could cause this. I run premium fuel in it. When your cruising along 55-60mph it want to surge a little,You will see the rpm jump slightly like it wants to down shift. and you can also feel it too. I dunno. Any ideas would be great. btw it has a 5.2L and its 4wd. Also the previous owner straight piped it to do away the o2 sensors. Could this be the culprit all along?

 

Need O2 sensors in there...... Your truck should have two. One pre-, and one post-cat. If you don't have a cat, just do the non-fouler trick on the rear sensor.

 

^^this is true, however, i had similar issues, and the culprit turned out to be the pcm flash. Mine would surge ~200 rpms when in O/D with the TC locked up (which happens at around 55-60, or 35-40ish if you have OD off, and is electronically controlled). The surging is the result of the TC locking and unlocking (which feels like it wants to downshift) due to the pcm sending faulty signals.

Take it to a stealership and have it flashed. Price depends on where you live, and the mood of the mechanic. I've heard of it being free, however, in my case it was ~$70. I was told that as the software on a pcm ages, it tends to "forget" things, which is why this occurs.

 

Did you ever clean the throttle body, especially around the IAC port?

 

The 55-60mph surge of 200ish rpms that you couldn't feel but could hear was due to a melted spark plug wire on my truck.
I did the re-route (TSB on how to arrange the spark plug wires) and put new wires on at the same time. When I took the old wires off is when I saw where the headers had melted one of them.

 

I hate surprises like that...... Changed the plug wires on my van..... because it had a dead miss that I just couldn't find. Everything looked good... but, when I was RE-redoing the wires.... one of them disintegrated in my hand. There was NO connection going on there..... I was.... annoyed.... It just couldn't have done that the FIRST time, now could it?

 

Thanks guys, Im gonna look at them closely when I get off work today. I went by the stealership, And thats exactly what they are too. No sir we have to put it on the diagnostics and see whats wrong. We pay a lot of money for our programs and we dont just do these kinda things for free. So I mentioned the BAIL OUT they had received and told him to to use ky on the next customers. uuuuuuggggggg

 

So what's the deal with the o2 sensor's?