Hello, I have a friend who has a 1998 Isuzu Trooper, V-6. and100,000 mileswith a check engine light that refuses to go off and has stumped the local mechanics. We had the codes read at Auto zone and it showed a PO 101 code. The mechanics had already replaced the oxygen sensors and the MAF. Once clearing the codes the light goes off for a couple of days and then comes back on. The wierd part is that the vehicle runs fine. Anyone have any ideas for a fix? Thanks,GWB