Stop in for a cup of coffee

So have a question, why does engine idle faster after x pipe install, BUT drop more RPM when put in gear?? Nothing else changed. B4 x pipe, it would idle at about 1200 RPM in gear, real nice running here. NOW it idles 1000 in gear and the more I turn up curb idle, the harder it engages into gear. BUT still stays at 1000 rpm?