so my check engine lights on the codes are PO171 & PO174 any idea what it could be ?lol thanks guys.

 

Bump. anyone? LOL

 

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.

 

its not hard at all, i would guess that ur intake gaskets r bad. heres a link

http://www.explorerforum.com/forums/...ht=P0171+P0174

 

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.

 

there is 3 little ones right under the plenum, then one under the fuel rail and one underneath that between the upper intake and lower intake. might as well change both, not much more work to do both.

 

cool ty do u know any videos or pics that will show me how to change the other ? just dont wanna screw it up to bad. :)

 

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?

 

Yes that it

 

kk sweet ty lol 99.99 for that but hey if i need it no big deal :)

 

Just did the rubber elbow fix on my 4.0 SOHC, but I just realized your's is a '98 with the OHC. Sorry