2004 Expy Rear Left CAT Knocking

[Peter Brown]

Hi y'all, I have a knocking under my rig that was diagnosed with a mechanic's stethoscope. No CEL. Normal performance from engine otherwise. Mechanic wants 600.00 to replace one left rear CAT. Is this a fair price?

Should I replace the entire system or should I look into replacing whole CAT system?
90.5K miles on rig.
Happy Holidays,
Peter

 

[riphip]

Would not replace myself. Would wait until after winter, get underneath and find noise myself! Headphone-stethoscope tool is cheap and useful for other projects.
Bad CAT at 90.5k....I don't think so . Maybe hanger or something else rusted or loose heat shield

We say: MERRY CHRISTMAS Y'ALL down here

 

[Hamfisted]

Do you have a muffler shop in your area? You can stop in there and get a second opinion. But like riphip said, it's pretty rare for a Cat to go bad at that mileage. But a muffler shop can put it up on a lift and give you a better idea, and be a lot cheaper if you do have to replace it.

 

[Don Hall]

Hello, Peter Brown.
Just some info:

My 2004 (dual cats, each side) lost a left-front cat after 10 years, and very low mileage.
My sage muffler shop suggested replacing both left cats, as the front cat can take-out the rear, (plus add to the bill).

Was charged $290.00 & $280.65 for the cats, plus $85.00 total labor. Add sales tax $48.51 = $704.16