Here is the deal. I have a 99' Jeep Cherokee with 207,XXX on it. I just got a check engine light yesterday. I hoked up my OBD tool and got 2 codes.

P0171: System too Lean (Bank 1)
P1195: Slow Switching O2 Sensor Bank one Sensor one During catalyst monitoring.

The symptoms are: When coming to a stop my RPM's drop between 500 - 750 the normal idle is at 750 RPM's. after 2 to 3 seconds it's right back where it's supposed to be at 750 RPM's. I have noticed that it is a little bit starved when i take off quick from a stop, it bogs down briefly.

If any one can give me some advise that would be great. I am thinking that it might just be the fuel filter.

-Thanks

 

Better hope it isnt a fuel filter... That takes a tank drop to change out

 

You have a vacuum leak someplace around the intake.

 

thanks, I'll look into the vacuum leak.
do you have any ideas as the best way to approach it?

 

If u have an O2 sensor code, try starting there. The code is indicating the upstream O2. It possibly could also be a faulty TPS, IAC sensor, dirty IAC passage way, etc.

 

yeah start simple as a vacum leak first, sometimes the littlest things can cause a head ache.in the mean time dont stress over it lol

 

They (vacum leaks) are a pain in the azz to find. I had the same problem a while back too. It turned out to be both O2 sensors. Don't skimp on them either.

 

been driving all day and have noticed that when under load (going up hill) it really dogs out when trying to hold at 2000 RPM's. the whole jeep starts to shake until i kick it down to down shift.

In response to the vacuum leak responses: I have been searching for a problem for a wile now. i followed all the hoses around the intake and have had no luck with any crack or anything that would lead me to believe that it was a vacuum line.

any other suggestions would be greatly appreciated to to the fact that it is my daily driver and the problem seems to worsen with each mile that i have put on it today.

 

What does anyone think about it being the catalitic converter. If so, can i just cut it out and put in a piece of straight eghaust pipe to reconect it? Or am I goung to have problems with the computer?

 

any help on this topic would be greatly appriceated. I am heading out of town and only have a few hrs before the jeep needs to make a 300 mile round trip. Just a little nervous about headind out in the current condition.
-Thanks everyone-

 

don't do that, its illegal.

 

Just replaced the upstream O2 sensor and the problem seems to be fixed for now. Thanks everyone who responded to the question.

 

having problem with the computer is not a big deal... having problem with the law is going to be worse... having problem with this forum is most likely....
If cat is bad.... change it for a new one

 

500 rpm is the correct factory idle speed if everything(map,crank,both O2,idle air,TPS,coolant temp sensor, etc) are working correctly. 700 rpm seems to be common if O2s are old.

 

I thought the FSM said 700-750 rpm idle speed....500 rpm seems low or was there a Harley-Davidson edition XJ. LOL