I need help diagnosing an issue with an 01 Nissan Sentra 1.8L GXE. Many thanks in advance!
On a cold engine, the engine sputters and stalls once I put into gear.
On a warm engine, lack of power and hesitation under ~2k RPM. Gets worse the more I push the throttle.
No idle issues in P or N ever. No idle issues when warm in any gear. No unusual noises. No impact on MPG.
Has been like this for at least 1k miles.
MAF and ECM replaced 7 months ago. MAF just cleaned.
New filter (Purolator)
New spark plugs (NGK Iridium)
OBD II readings seem reasonable for throttle position, Coolant temp, and air temp.
Vacuum test shows: rapid fluctuation 18-21 at idle, rapid fluctuation bet. 19-23 at 2k RPM, crazy fluctuation 13-22 at 3k, and a steady 21 at 4k. Video: http://www.youtube.com/watch?v=msCholgxizA
At first I thought was a vacuum leak or a faulty EGR diaphram, but the vacuum test makes me think I have a broken/sticky valve... Please advise.