OK to run w/o cat?

I've heard that late model engines(computer timed) don't take kindly to having the cat removed. Is this true, and can I retune the computer to allow for the change? My thought process here is, my cat is about fried and I'd rather spend the cash on a bigger diameter exhuast with a high flow muffler, rather than a restricting converter. Plus, I believe that the engine will run cooler by removing the cat. If you've some experience with this, or know the specific ramifications of removing the cat, your assistance would be greatly appreciated. TIA

Cheers,
goldxj

I gutted my after market catco and have a 50 series flowy with 2.5" tail pipe on my '91 4.0. I'd say it definately smells like its runnign a bit more rich now but i noticed no drastic drop in power, maybe a slight slight loss in bottom end torque, but high up in the revs it definately gained some horsepower. Also it will definately be alot louder, not intolerable but alot more interior resonance too around 2k. I'd say go for it though if ya don't mind the noise, its alot cheaper! Its also very illegal if you are picky about keeping your jeep in tip top legal shape, i'm not thats why i did it.

Eric

Standard disclaimer: What you are proposing to do is illegal. Federal law prohibits removing or tampering with required emissions equipment.

Second, I'd estimate that about 80% of the people who have tried this reported either a net loss of low-end torque, or no change. Some report a gain in high end horsepower, but unless you run very steep gearing this won't help you.

Bottom line is, you're much better off running a high flow cat than breaking the law and leaving it off.

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