Hey guys So I recently put on an 06 Stock STI muffler, with 2.5 inch piping from the cat back with no resonators. Occasionally after I drive and I'm sitting at a stoplight or something my revs will be at 1000-1800 rpms. I know my regular idle is usually between 400-800 rpms, so is there anything I should worry about? I was thinking maybe it was O2 sensor but I want to know what you guys think first.
Thanks
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