Hey all.
I've searched all the rattle threads have *think* I have a twist on them.
2000 Ram Sport 1500 with the 5.2L. 75K miles. Slight, very slight rattle from under the truck at idle and when revving the truck in Park.
Now, last weekend I updated my last will and testament and then had my wife sit in the truck and rev the engine in Drive (with her foot on the brake) whilst I laid underneath and listened. SERIOUS rattle from the cat/trans area. Being so close together (the cat and the trans) I couldn't really tell beyond a shadow of doubt if the rattle was coming from the cat. It sure sounded like it tho.
Anyway, all you folks that have had this rattle - did it rattle like crazy all the time or just when accelerating? I mean, could you hear it in a drive thru, for instance, when the truck was in Park and idling? Just looking to be sure before I take it in to get the cat replaced. Also, should I replace the O2 sensor that sits next to the cat at this time as well?

Sorry for the long post - new here.

 

if you get under the truck and bang on the cat or pipe just after it with your hand you will hear stuff ratteling around if your cat is bad. And yes I would replace the o2 sensors when replacing cat

 

oh and you can get a magnaflow free flow cat for like 200 versus the factory one for whatever ungodly ammount they will charge you lol.

 

http://www.discountexhaustsystems.co...Part-Catalytic Converter
check these out

 

it may sound stupid, but if you hit the cat and it doesnt rattle and you dont think thats it, check all you exhaust hangers, i had a rattle that occured while idleing or in park and all that and when i checked the cat and saw nothing, i looked around and saw one of my hangers broke off...and the exhaust vibration caused the hanger to rattle on the frame and stuff..so i taped it up to check and it went a way. so i replaced them all... like i said it sounds dumb, but its always possible

 

Thanks all. I whacked that cat pretty hard and it does sound like something is loose in there. All of the hangers and shields seem to be ok and out of the way. Do most exhaust shops also do the O2 sensors?

 

ya they all should do them.

 

the one i was going to go to doesnt...they wouldnt even do anything before the cat. they said witht he 01 rams they would mess up the air/fuel ixture. i even asked about a highflow cat they said no.. but i still have the stock cat on mine with 124k miles..pretty sure it needs replaced

 

does the rate of the rattling noise steadily increase with steadily increased rpms?

 

Heat shields are a common problem, mine is rattling right now since one corner broke off the cat, I've been too lazy to weld it back up. I've had heatshields come loose a couple other times on different vehicles too..