Bank 1 lean

[05warrior]

other than bad o2 sensor, what could cause this. Just a side note, my muffler leaking from everywhere, can't really call it a muffler anymore. If the bad air from my leaking muffler is getting to my rear o2 sensor could that cause the whole problem or am i headed in the wrong direction?

[Jeffb_79]

I would say O2 sensor or cat. Sounds like your exhaust is pretty old and tore up, might want to start with replacing it. If the exhaust is that bad, I can only imagine your cat is running on its last life.

[05warrior]

I'm more worried about my muffler, because the welds on the pipe going in/out of the muffler body itself are gone and there is about a 1/4 to 1/2 in gap all the way around that weld on both sides.

[Jeffb_79]

I wouldn't think a shot muffler would cause any problems other than extra noise. The sensors are upstream from the muffler. The muffler being in that bad of shape though could indicate that the rest of your exhaust is shot. If your cat is clogged or damaged it could cause the problem. It could also damage your O2 sensor.

[Ghost00TJ]

I'm with Jeffb_79 on that as much use you give your rig, I remember a pic of it floating down stream :D but that with holes in the pipe allowing dirt in the cat could be messed up.
I thought the O2s were up stream of the cat? If so the lean would be from a faulty O2.
I have even seen them show check engine and read with a code reader when the weather gets wet.

Maybe having vertualy no muffler causes it to read lean because there is little back pressure

[05warrior]

I was thinking the o2 sensor close to the muffler is getting bad ambient air because of the screwed muffler and theat be causing it to cause problems.

[smccollamjr]

I saw the subject and thought Bank One had put a lien on your Jeep :D

[fireboy52]

I dont think you muffer being shot would cause this. I dont even run a muffler I just have a turn down coming off the cat and slightly past the skid. I would think if your trouble was the muffler I'd get the same for not having one. The I6 puts out a decent amount of water compared to most engines so its not uncommon for stock exhaust to rust away from the inside. They should be able to break down the problem further than that with a scan tool and that would save you money. If you just throw an exhaust or O2 sensor at it you are wasting money. Just my 2 cents.

[05warrior]

I dont think you muffer being shot would cause this. I dont even run a muffler I just have a turn down coming off the cat and slightly past the skid. I would think if your trouble was the muffler I'd get the same for not having one. The I6 puts out a decent amount of water compared to most engines so its not uncommon for stock exhaust to rust away from the inside. They should be able to break down the problem further than that with a scan tool and that would save you money. If you just throw an exhaust or O2 sensor at it you are wasting money. Just my 2 cents.

That's how I know that Bank 1 is lean is from a scan tool, that's all they told me was that bank 1 is lean and that is caused from a bad o2 sensor.

[05warrior]

So, I replaced my front o2 sensor and my Gas Mileage has improved drastically. Thanks for all your help

[Jeffb_79]

That's good.
I would still get your cat's checked. If it's going, or gone, that could lead to a short life for your 02 sensors.

[Jeffb_79]

That's good. I would still get your cat checked. If it's gone/going, it could lead to a short life for your 02 sensors.

[05warrior]

yeah, as soon as the wife gets a damn job the whole exhaust from the head pipe back is getting replaced