This just started in the past few days, my 04 WJ will crank up fine, but idles at around 1,100rpm. Sometimes its will crank up and idle at around 700 but as soon as I put it in gear it jumps to around 1,100 again. I also noticed the other night that my exhaust manifold is glowing red and the exhaust is hot as . Any ideas? TPS, IAC, 02 sensors? i know it could be any of the above or a combination but I was just wondering if anyone else has had this problem that could give me a place to start before i just start replacing sensors that dont need to be. Also my CEL is NOT on, i figured if it was an O2 sensor it would be throwing some sort of emissions code.