91 Xlt Runs Like S%(!@

[Joes4x4Ranger]

OK,
I just fixed an exhaust leak as directed in a previous post. The leak was upstream of the O2 sensor and a major suspect for a gutless 4.0. The CAT's did look plugged so at the advise of a "certified" tech I gutted the CATS and put the empty shells back on my rig.

Now the thing idles like S^%$!!! very rough idle "Rolls" between 400-600rpm. Above Idle it seems much stronger than it was before, it accelerates much better. Its a manual trans, are there any vacuum lines around the Y pipe I may have knocked loose when fixing the exhaust leak?

This rig has a new IAC, spark plugs, clean air filter, I cleaned the MAF, sprayed air intake/ throttle body cleaner all over the throttle plate and wiped clean as far back as I could reach. I inspected the vacuum tree and sprayed starting fluid all around the intake manifold with not a single hint of an idle change. I'm stumped please help

 

[Dora The 4x4'a]

well dang..i'd say y ou did a rather extensive tune up..and y oru results are surprising. GLfred advised you correctly and is a certified tech..

i would start here incase you didnt do it..

with all of your tuneups, and your now-repaired exhaust. your EFI system all needs to be rebooted!!

disconnect your battery for a good ten minutes (both terminals)
reconnect and turn over
let it idle for a bit
then take it around the block doing normal driving
then do a couple WOT passes

giv the harddrive a couple diff scenarios so that it will be spittin and breathin the correct rates for your whip to run right.