I've got an 04 with 3500 miles on it I bought in December. The last month or so it has developed the disconcerting shudder /rough start when cold. Typically, this only happens in the morning. The RPMs flutter about around 400 - 600 and then go to a normal level. Any ideas? Could the MAP sensor be causing this so soon? I don't think it is ECU related to humidity or temperature as it has been fairly consistent lately.

 

Anyone?

 

Like many pre-04s, this is not an uncommon thing. Usually, when environmental changes occur such as temp, humidity, air pressure, etc, changes overall, the ECU's on some cars need a bit of time to "learn" to deal with the low idle upon cold start. Some cars will even start, rev up for 1/2 a second, then die. A second start usually is required with no other bad symptoms to follow. Let it "learn" for a few cold starts WITHOUT you doing anything with the throttle. IE, don't help it by giving it gas or it will take that much longer to learn. If it doesn't learn in about 4 - 5 cold starts, then do the "MAP whack" and ECU reset:
http://forums.s2ki.com/forums/index.php?showtopic=209708