Cat Rattle?

2000 GMC Jimmy 4.3L 2WD 153k miles. Just started hearing a rattling noise when at an idle underneath the truck.

While I was underneath checking for leaks after an oil change I thought It sounded like the Cat. I banged on the Cat with My fist and sure enough, it rattled, so I guess this means it is time for a new Cat.

DUH! :sarcasmsign:

Glad it ain't the Tranny!

See http://www.catalyticconverterwarehouse.com , for OEM replacements.

I had one with a heat shield around the cat that had like a 1 inch gap. Turned out gravel had gotten in the heat shield and did the rattle.

No Heat shield on this one. I got a quote from a Muffler shop for $250.00 for a new Cat and a new Muffler, installed. Sounds pretty reasonable to me.

Whaddaya Think?

If they install an el cheapo converter, it will continuously set P0420 and turn the SES light on. I've had good luck with Walker direct fit converters, (just a suggestion), not that difficult to install, it's bolted on, no cutting or welding involved.

IIRC Rick most OEM direct fit replacement converters for these trucks are the entire y-pipe and converter together so the entire y-pipe has to be replaced. You can get a universal converter and have it welded in. Some hi-flow cats may trip the po420 code after some time as they break in.

I am not sure if it still in effect, but a number of years ago, Arizona would only allow specific cats by Manufacturer to be installed into a vehicle registered in Arizona. According to my understanding, the "approved" cats met the requirements for burning off unburned fuel to the state specified levels, which reportedly prevented the El Cheepo's from getting in.

I have used this Muffler shop in the past with no complaints, so I had the replacement done last week and so far wso good. I am hoping to see a bump in gas milage. We'll see.