Check engine light & knocking

Black_Dog · **Posted:** Sat Mar 15, 2008 7:00 pm

Last week after a rare North Texas snowstorm my check engine light came on and I began hearing a soft knocking while coasting between 15 and 20 mph. The KJ has about 47K miles on the odo. I’ve gone through a couple tanks of gas from different stations, so I don’t think it’s the gas. I suspect a small in an exhaust component. I haven’t bothered lifting and inspecting underneath because I’m taking it in for a state inspection on Monday anyway (hopefully whatever’s wrong is covered by warranty). Any ideas?

Jeep Dawg · **Posted:** Sat Mar 15, 2008 7:07 pm

I had a problem like that a LONG TIME AGO with my 03 sport. It was about 30K and I heard that knocking. It almost sounded like low oil and lifters saying, YO WE NEED A DRINK.

One of my coil packs were loose and so was the spark plug. After I cranked it down, the knocking noise went away.

Now, FYI I change my plugs every 25K. I Must have not made the coil pac tight enough and the plug too. They must have worked there way loose.

I would try that fist. see if your plugs and coil pacs are loose, Also check if you are low on oil

Dje Ryu · **Posted:** Sat Mar 15, 2008 8:06 pm

have you checked to see what the error code is that's causing the CEL to come on?

http://www.allpar.com/fix/computer-codes.html

Black_Dog · **Posted:** Sat Mar 15, 2008 9:56 pm

Thanks for the feedback.

Jeep Dawg: Oil level okay. I just pulled the plugs. They and the coil packs were tight. Need to replace the plugs, though. Didn't have a chance to get new ones tonight but I did re-gap them.

Dje Ryu: thanks for the link. Got the message P0137 -- HO2S (heated oxygen sensor) Circuit Low Voltage Bank 1 Sensor 2. Next question: what does that mean?

Dje Ryu · **Posted:** Sat Mar 15, 2008 10:12 pm

Most likely: the clip that holds the wires to that o2 sensor broke and the wires are rubbing against the front drive shaft. The fact that it shows up after snow probably means the wire isn't rubbed through yet but that the moisture created enough of a short to throw the code.

I only know that 'cause it happened to me and it seems to be a common problem. The sensor is the one behind the catalytic converter on the driver's side... almost directly under the driver's seat, actually.

Black_Dog · **Posted:** Mon Mar 17, 2008 10:33 am

Dje Ryu wrote:

Most likely: the clip that holds the wires to that o2 sensor broke and the wires are rubbing against the front drive shaft. The fact that it shows up after snow probably means the wire isn't rubbed through yet but that the moisture created enough of a short to throw the code.

I only know that 'cause it happened to me and it seems to be a common problem. The sensor is the one behind the catalytic converter on the driver's side... almost directly under the driver's seat, actually.

You're exactly right. The cables are out of the clip and were rubbing against the front drive shaft. One of the wires has worn all the way through and another has been stripped of insulation down to the copper.

The stealership wants $74.06 for a new oxygen sensor (they say it's a bargin). As much as i hate to have a jerry-rigged electrical repair on the underside of the Jeep, for now I'm just going to fix the wires with in-line terminal conectors.

Thanks for your help with this.

Dje Ryu · **Posted:** Mon Mar 17, 2008 2:39 pm

That's how mine has been for months now. It still throws the CEL on whenever it gets wet (I taped them up pretty well so I'm talking 20"+ deep to get wet) but runs fine and the code goes away as soon as it dries out.

ATXKJ · **Posted:** Mon Mar 17, 2008 3:09 pm

Moparparts is asking about $31-$33
http://www.trademotion.com/partlocator/index.cfm?action=getJointLocator&siteid=214583

Check engine light & knocking

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