Check engine code???

The first thing would be to make sure the hose or whatever is securely hooked up still. You may have a bad O2 sensor but I'm not sure how to check them. Since you just went wheeling, make sure there isn't any mud or grit caked up on something.

Just replace the O2...there's really no good way of testing and even if it technically was a good reading on a '97 with even an average amount of mileage the sensor's response is likely degraded to damn near being useless. Remembering that when running in closed loop the ECU makes constant changes to the injector pulsewidth in order to maintain 'optimal' (not necessarily stoichiometric) air/fuel ratios...if the response time is down on the sensor it'll be reporting old and/or false values to the ECU. They're relatively cheap from local parts houses and are easy to replace. Make sure that there's a dab of antisieze on the threads prior to installing the new unit as it'll make any further replacements much easier.

Also make sure that you don't have any exhaust leaks or cracks in the manifold upstream of the O2 as it'll read lean with the fresh air mixed into the exhaust gases.

--Ian

the o2 sensor is in the pipe
should be just before the cat.
i have never had a problem with aftermarket sensors
try auto zone
they normally dont take to long to replace
just a half hour or so
not even that
i think there is only one
but cant remember the last time i looked at a 4cyl tj
hth

changing one out is pretty easy if you got the right tools.i just happen to have the right socket. your welcome to stop by after you pick up a new one up . call around for the best price from the auto parts stores, and i'll do the installation for you. drop me a line on when is the best time for you.

Quote from "SarasGP"

I went to get a PCV valve and was told that there isn't one. I may be only a dumb girl, but that's the first time I've ever heard of an engine (fairly recent model engine) not having one.

So I'm left with getting O2 sensors (note the plural) at $70 per so I'll have to wait 'til next week to get them. Blackflag, stand by for a PM next week.

The only other thing I can think of is the fuel filter, but that's a total PITA 'cos it involves taking out the fuel pump.

(Can you say frustrated?)

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actually tj's dont have a fuel filter
they have a sock on the p/u tube in the tank
and as far as i know it is not replaceable

Quote from "jeeprubicon"

actually tj's dont have a fuel filter
they have a sock on the p/u tube in the tank
and as far as i know it is not replaceable

2 filter socks (one on the outside of the sending unit assembly, one on the pump itself) and a filter integrated into the regulator assembly...I've become intimately familiar with the inner workings of a TJ fuel system in the past couple months troubleshooting my issues...

FYI if someone has a fuelpump go the pump assembly _is_ rebuildable, there's a guy on ebay that markets the pump with both pickup socks for ~$80....if you're short on time and have more $$ than brains, though, Newark Jeep usually keeps a couple assemblies in stock. They're $219 cost...like $3-something normally.

--Ian

Quote from "SaraGP"

went to get a PCV valve and was told that there isn't one. I may be only a dumb girl, but that's the first time I've ever heard of an engine (fairly recent model engine) not having one

My 93 XJ didnt have a PCV valve either. Instead it was called a CVC or something like that. I could have gotten a new one for a lot of money but instead decided to clean the old one out with a degreaser and some compressed air. Worked well and managed to clean all the gunk out.

There has to be a valve somewhere on the crankcase or valve cover.

Just a thought.