One more thing you may check is your fuel filter, although I am not familiar with the 4.0 (I have the 4.2). To answer your question (and you better not work for the Feds <img border="0" title="" alt="[Wink]" src="wink.gif" /> ), yes my catalytic converter is removed. On 258 Jeeps, there are no sensors, etc. on the catalytic converter--the last sensor is the oxygen sensor on the exhaust manifold. However, you will have to make sure that your computer is not taking any readings from your cat (like another oxygen sensor, etc.) that would confuse the computer if it is missing. Also, if your converter has a return tube that brings exhaust back to the engine, make sure it doesn't have a sensor on it--if it just routes the exhaust back into the intake or something then you should be ok. Another alternative is to take the cat off, knock out the screens on the two ends, bust up the inside, and gut it out. Some guys have suggested this because it will get you through a visual inspection.
'85 CJ-7, '90 Sahara, '01 Sahara.....a proud Jeep owner since '97