When my IAC went bad the idle would fluctuate wildly. I don't know if the IAC would have much effect when you are out of the idle range.
When my cat finally broke apart enough for the pieces to get sideways and clog the exhaust flow, the tone of the exhaust sounded very muffled and the Jeep wouldn't go over 20 mph. Before it got this bad the pieces would rattle loudly.
'96 ZJ, 4.0L, 42RE, NP242, stock D30 and D35-LS w/ 3.73, 4-1/2" lift, 32" BFG ATs, Magnaflow, JKS track bars and disconnects, spare tire carrier, Optima red top, ROLA roof rack, KC SlimLite driving lights, CB and Yaesu ham radios, GPS
Last edited by ZJJay; 04-09-2010 at 11:26 PM.
Reason: Correct another darn typo.