Engine has 27000 km on it, and only P0507 was set - I followed all of the troubleshooting steps, and fixed the usual problems (new intake gaskets and plenum, new IAC, MAF and TPS, carefully inspected and thoroughly cleaned throttle body, verified no other vacuum leaks). The engine now idles very smoothly, however the idle speed out of gear is around 850 RPM and a bit lower in gear (AC off). Manifold pressure and air flow seem normal. Since I think it should be around 600-700, this has prompted me to check this forum to see what else could be causing this, and if in fact this is normal for reduced vacuum due to engine age. Any thoughts?