Id Of Catalytic Converter.

[govener71]

I have been on here a few times now doing things to try and fix up a truck I bought a year ago. It is a 1999 GMC Sierra Ext. Cab with a 5.3l and 4x4 Z71. 192,000 miles.

 

I am looking to clean up my catalytic converters. I would like to put a couple of replacements on it (Universals). Does anyone happen to know the ID of the converter that I will need? I have seen 3", 2.75", 2.5" I am just not sure what the size I would need.

 

Sorry if this has been discussed before after a short search i was unable to find a definitive answer. Thank you.

[Mckenzie]

Why do you want to replace them? Are you throwing any codes? Do you think there clogged?

[govener71]

I just had the heads replaced because of many miles, coolant in the exhaust, and it seems to be becoming a bit sluggish while on the highway. I also read in another post to check by bumping the converter and listen for a gravel sound. Mine must be starting to fall apart because both are making a rattling noise. I am going to replace them not only for those reasons but I like to tinker. It's the first car I have ever really worked on and I love it. So I am slowly finding things to fix or improve. all improvements and fixes have been attributed to this forum. Thanks all!

[AirForceAngler]

Get some calipers, climb underneath there and measure the input and output side of the cats. Or take it to a shop. As much fun as I have working on my truck, exhaust work is not something I particularly enjoy, especially a truck with 192K on it!

[HawkScot]

and remember that your old cats are worth some money at the scrap yard.

[govener71]

Thanks for the advice!