quick o2 and exhaust question

Jeeps been running really rich. I had broken the O2 sensor and it took a few weeks till I had time to replace it but I had to drive that time with no O2. Replaced it and it doesn't run as rich but still runs pretty rich, can smell fuel on warmer days.

I do have a leaky exhaust manifold gasket and wondering if thats throwing off the O2 sensor causing it to run rich. Also does the computer read the O2 sensor right away or do you have to unhook the battery for a few secs?

Yes, the leak in the exhaust manifold will thow off the O2 sensor.

The computer reads the O2 sensor constantly while the Jeep is being driven and adjusts the fuel load from that data.

and therfore would run rich? excess oxygen in exhuast so computer says it could use more fuel, I would suppose.

Not to ad insult to inury but running rich may also screw with the CAT. You might also wanna do a quick check of all the temp sensors and/or thermostat to make sure that the ECU is getting the right temp signals. If not, that will keep it in open loop mode so the 02 sensor is not doing anything.

no cat.... :eyebrows: