I have a 98 jetta 2.0 and i just replaced the pcv valve. When i did this i removed the valve cover to replace the pcv. i went through and completely cleaned everything the air filter(K&N), MAF, throttle body and the top part of the intake manifold. All of the gaskets were replaced. When the car starts the idle will go to 1500 rpms and then will slowly make its way to about 900rpms. when i drive the car and push in the clutch the idle will go to 1500 rpm and will stay there untill the car stops moving. When it stops the idle will slowly make its way to 900 rpm. Does anyone know what is causing this problem?
Also the car had some problems with the idle before this work was done , actually i was hoping what i did would fix it. After long trips the car would idle rough when started after the trip. Rough enough to make the CEL go off. the idle did the same thing described above but the idle would start at 1100 rpms not 1500.
Does anyone know what is causing this problem?