97 jeep wrangler 2.5 running lean

Apr 22, 2009

-   Hey Guys ,my friend has a 94 Cherokee country 4.0l with the 5 spd.It has failed the emissions test twice having a very high 'NOx' reading.Everything else is great and well below what is needed.The O2 sensors were replaced,new cat and exhaust.Map sensor is new,idle control sensor,throtle postion sensor.New fuel filter,plugs cap and rotor...Honestly we are scratching our heads here trying to find the problem.Oh before you say it,there are no vaccuum leaks either.
Can anyone help please? -   jays jeep

Apr 19, 2009

-   my 97 wrangler is giving me the running lean code and i found a exhauset leak right after the head and expected that to fix it and it did until the car warmed up then it started bucking and loss of power issues not to mentions it seems to be getting bad gas mileage. i am not sure what to do-   dkking1

Oct 15, 2008

-   ive been having the same problem, replaced the exhaust manifold and both 02 sensors... running a little better but still has lagging performance and gas issues. high idle when cold, slightly rough running when hot-   frustaci23