ok, i dont recall the actual description of 1404, but it basicly means your egr vavle postion shows being open when the computer wants it closed. i had this on my personal car around 115k, put on an egr, no trouble since. as i recall a new gm egr was reasonably priced.

i would replace the egr first, clear codes, and see if the misfire show up again, as unwanted egr flow could cause the random misfire. however if the coil terminals were coroded, i'd go ahead and fix that too.

on the coil packs, the only reason i've replaced them before was for corroded terminals, usually its the top/plug wire terminals, but i have found the bottom terminals to the igntion control module corroded as well. just pull the wires off of the coils and see if they look shiney and new. if one or more is corroded replace that coil pack and affected plug wire(s). they're easy to change if you need to. take off the 2 plug wires, take out the 2 bolts holding it down(5.5mm headed) and pull the coil straight away from the ignition module. install in reverse. if all the teminals look good on the coil packs, and if your wires are original, plug and wires would be my next guess. you can tell if your plug wires are original, if they are numbered, theyre original. when replacing always use dielectric grease on all your plug wire terminals.

 

Thanks man i think that is exactly whats wrong with my car....im looking for a egr right now i see they have one in autozone for 115 dollars i wonder how hard it is to fix? i heard autozone is not a good place to buy your car parts...any advice on where i should buy it? you guys are freaking awesome. if it wasnt so cold right now i would replace my thermostat myself i dont have a garage [:@]and im scared i might mess it up i do have that book from autozone that tells me how to fix things on a monte carlo so i might just read that. wish me luck guys.

 

start by seeing what your price on a gm one is, sometimes theyre cheaper than aftermarket, or if its only a couple bucks more i'd get a gm. gm would be my first choice, dangerzone is typicly my last choice unless i know its the exact part and brand that i'm looking for. as for installing it, pretty straight forward job, i think getting the exhaust tube pulled out of and back into the egr is the hardest part of it.

 

when changing my thermostat am i suppose to drain my coolant?

 

if its never been changed, this would be an ideal time. if the coolant isnt very old you could drain it and reuse it.

you dont have to drain it, but on a 3400 you will lose a significant amount of coolant changing the thermostat. the fastest way to get the job done if you were on the clock would be throw a catch pan under the car and just start changing the thermostat, let the coolant fly, afterwards drop the car off at detail and tell em to clean up the mess under the hood :P