# 1997 Ford Ranger with cat failures

**URL:** <https://community.cartalk.com/t/1997-ford-ranger-with-cat-failures/117202>\
**Category:** Maintenance/Repairs\
**Tags:** catalytic-converters, ford, ranger\
**Created:** [May 11, 2018, 4:40pm UTC](https://community.cartalk.com/t/1997-ford-ranger-with-cat-failures/117202 "2018-05-11T16:40:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![FrankBSimpson](https://avatars.discourse-cdn.com/v4/letter/f/db5fbb/32.png) [@FrankBSimpson](https://community.cartalk.com/u/FrankBSimpson)\
**Post date:** [May 11, 2018, 4:40pm UTC](https://community.cartalk.com/t/1997-ford-ranger-with-cat-failures/117202/1 "2018-05-11T16:40:39Z")

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I have replaced the catalytic converters in my 1997 Ford Ranger twice now and need to have them replaced again. What causes them to fail and how can I prevent it from happening again?

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**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\
**Post date:** [May 12, 2018, 12:03am UTC](https://community.cartalk.com/t/1997-ford-ranger-with-cat-failures/117202/2 "2018-05-12T00:03:04Z")

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- high mileage. do you drive a lot of miles every year?
- engine/cat design. it may be this is just typical of rangers. the 97 ranger came in 3 different engine configurations, which do you have?
- problem with the fuel/air mixture, have the fuel trims measured.
- rapid accelerations. difficult for the engine computer to keep the air fuel mixture in its proper range, esp in engines using a map sensor, which I believe is the case for your ranger.
- rust. do you live where they put salt on the roads in the winter?
- diagnostic mistake. sometimes a cat will be replaced when the cat isn’t he problem, it’s something else, like a faulty o2 sensor. what is motivating you to replace the cat? doesn’t pass tailpipe emissions? check engine light?

My 26 year old Corolla w/200k miles still has the original cat, and passed the bi-annual emissions test with flying colors recently.

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**Author:** ![oldtimer-11](https://avatars.discourse-cdn.com/v4/letter/o/e79b87/32.png) [@oldtimer-11](https://community.cartalk.com/u/oldtimer-11)\
**Post date:** [May 12, 2018, 7:03am UTC](https://community.cartalk.com/t/1997-ford-ranger-with-cat-failures/117202/3 "2018-05-12T07:03:02Z")

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Does your truck burn oil? Too much oil will clog a cat.