I have a 2003 Dodge Ram 1500 4x4 with 113,000 miles and 13,000 miles on the motor, I had it rebuilt because the old one developed a knock after me owning it for 15,000 miles. After it was replaced, I didn't have a pipe that came off the cat so it had the downsteam o2 sensor off of it until I got that fixed, but now that I have the full exhaust on it again, it sounds funny to me, when ever im going up a hill or slowly accelerating it sounds like it has a misfire, but I have no codes and no CEL, the exhaust just sounds like a steam boat, chug chug chug chug, but I dont seem to have much loss in power. The engine has a VERY slight shimmy at idle, but no knock. It has done this since I got it back from the place that rebuilt it, is this normal? I need to get it smogged and it just doesn't feel right. Help me guys, I'm honestly losing sleep over this. I have very little money and cannot afford to pay a bunch of repair bills if it fails smog. Thank you for taking the time to read this, any help is GREATLY appreciated.

 

Just thought I'd post a quick video to maybe help.

 

actually sounds like some sort of vacuum leak to me

 

So I opened up the engine bay and stuck my head right behind the AC rad and could hear a hissing that seemed to be intermittent, possibly a fuel injector? I checked the vaccum lines and one seemed like it could be leaking but not by much, I have to investigate further. Like I said when I stuck my head in there I could hear an intermittent hissing that seemed to be the cause of the engine running wired, and it sounded like it was coming from inside the block, going to take it to a shop on Tuesday and get it looked at. I'm really hoping its not anything serious as I have no funds ATM.

 

So I got my truck smogged today, PASSED with flying colors, But this still doesn't explain the weird exhaust flow, still gonna get my valves & lifters checked out.

 

I remember my truck sounding like this when my egr was plugged with carbon, but it was also rough idling and dying on occasion. You didn't mention yours doing that. The sound reminds me of how the truck sounds after you pull the fuel pump relay before it dies. Glad you passed SMOG. Good luck. Nice wheels and tires btw.