Explorer Cat Convertors

[explorer99sport]

My truck has 160000 miles and was wondering when is the best time to change the cats, it is not throwing any codes but i am back for summer and had some time, thought maybe a good thing to replace them.

 

[ranger7ltr]

After replacing my engine...

I felt there was some restriction in the exhaust and it wasn't the muffler....I am going to find a shop that can weld stainless and then replace all 4 with these Thunderbolt - Spin Cat units from www.performance-curve.com

I won't have to worry about the old cats being a problem asmine has 169k on the originals and with a new engine I feel I need new convertors as well...

I am using 2 2.5" Thiunderbolts for the rear ones; 1 with no O2 sensor boss and 1 without... And 2 Thunderbolts for the front 2...I don't remember what size they are; I think they are 2' or 2.25"...