They should be lean bank 1 a bank 2. This is either caused by unmetered air entering the engine, or both the o2 sensors magically failed at the same time... But very unlikely. I bet your milage has slipped too. Check for vacuum leaks and broken airlines. Also could be your intake manifold gaskets.
I know thats a common one for the 4.0 SOHC, almost 100% of the time its the 90degree elbow on the intake on the top of the engine under the top coolant hose. Definately check your intake hoses, they tend to crack at the elbows
yea i think thats the one and thanks for the replys . il check those elbows and my truck has about 195k on it lol just bought it tho love it and def willing to put the money into it just not sure alot about em. How hard is it to change intake gaskets?
Shouldn't be too hard. Just remember where all the vacuum lines and wiring plugs go. Take lots of pictures that you can refer back to. I've done it on a 2.5 and a 3.0 but not a 4.0. If you do end up doing this, I would clean the intake manifold with some intake/carb cleaner to remove some of the deposits caused by the egr valve.
thanks all and do u think its only the one gasket or should i change em both? the guy at autozone said there was 2 or something the intake and then the Intake Plenum gaskets. lol im car retarded sometime very sorry. the thing is ive evan worked in garages and know alot about cars just not this truck :) ty all again.
also i found this on autozone.com Felpro/Intake Manifold Gasket Kit comes with Permadryplus lower intake, upper plenum, valve cover gaskets, all miscellaneous gaskets. think that will be the one i need?