Hey all, I am having an Idle problem with my Evo 9.
When I coast to a stop at a stop light my idle drops to around 400 RPMs (a couple times it stalled out). When I let the car warm up before driving it the car runs fine, it's after i've been driving it for about 5-10 minutes when it starts acting up. Every once in a while when I coast to a stop the RPMs bounce from 400 RPM to 1.1k RPM several times before it settles back down at 900. At first I thought it was a vacuum leak, but my friends think it may be a O2 sensor going out.
Can anyone else help me determine what the problem is? Thanks in advance.