2003 Ford Explorer Q&A
2003 Ford Explorer Question: Vacuum leak
Pinch off all vacuum hoses with a pliers. If any changes occurs, it could be a leak. One particular area that is comon for these vehicle is the intake manifold gaskets. A propane method is a sure way of detection, but monitoring the O2 sensors is desired when doing so. The manifold gaskets usually are more prone to leak during cold starts. - Brian Glastetter
My 1992 Ford Explorer XLT 4dr 4wd Auto 4.0 V6 has begun suddenly running rough and the check engine light comes on. It happened after I replaced the O2 sensor, when I was reaching behind the engine...
The intake manifold O-ring gaskets commonly leak, causing stalling and poor idle quality; the Check Engine Light will illuminate.
EXPLORER RUN GOOD MAYBE GAS CAP, OR RE CHECK VACUUM LINES,SHOULD I CHANGE THE DOWN STREAM O2 SENCER, PLEASE HELP
The idle is rough, but smooths out and runs fine while driving. O2 sensors have been replaced also.