Sputtering, lack of power, rough idle

[noah7797]

So I've come across this very strange problem with my 97 Explorer XLT 4.0 SOHC. When I start it up it runs fine and idles smoothly at the usual RPM. After I drive it a few miles and it warms up, the idle starts getting rough, I lose power, and when I try to accelerate there is no power at all and the engine sputters to accelerate. My engine is newly rebuilt with less than 5000 miles and was professionally broken in. This problem seems have come about right after I had 2 new front 02 sensors replaced. I also have a custom exhaust with no catalytic converters. I'm looking to sell it soon and have taken it to 3 shops including a dealership and none have given me any answers. I've had the codes read and they are only for the catalytic converters. Any help would be appreciated. Thanks!

 

[keller_32]

Were new spark plugs put in with the rebuild? Id sure hope so, but this sounds exactly like the problem I had. 185000 miles on mine, kept having problems, but never stopped and thought of plugs. Didnt know how mine even ran in the condition those plugs were in. May be bad plug wires too. check both out