[seeless85]

Our '08 patriot has had an intermittent service engine light since this winter. We assumed a loose gas cap as it would go away after a while. My wife took it to autozone and they said it was an oxygen sensor. About 2 weeks ago we had it inspected (passed emissions test) with no issues. The guy at autozone couldn't believe that the car passed inspection with an O2 sensor problem, but the light wasn't on then either.

So my question since I haven't ever really worked on the Pat yet is, how many O2 sensors do we have? Is there any way I can tell which on it is without bringing it to a dealer with more sophisticated equipment and a charge? How hard is an O2 sensor to replace? Are there any tricks I should know? The car has about 34,000 miles on it and is due for spark plug change also. I have them I just haven't gotten around to putting them in. Could a faulty plug cause an O2 sensor to trip the service engine light? They erased the code at autozone and it hasn't come back on in two days.

The car has the 2.4L with cvt.

Thanks in advance for the help!

 

[harold]

did they tell you the error code number?

 

[seeless85]

no, my wife didn't mention a number. I wasn't with her at the time all they told her was it was an oxygen sensor. I am planning to change the spark plugs tomorrow. As of yet the light hasn't come back on.

 

[jloffermann]

I heard this once before not sure how valid or truth full it is...

quote "moister on the spark plug wires between the wire and plug" maybe sounds like that since it was intermittent? or even a bad connection.

p.s. I really advise the use of the normal copper plugs a member had misfire issues when he bought the $$$ platinum ones and when he got plain-Jain copper ones it went away... something about how the platinum ones worked differed from copper.

 

[Stonent]

I've had several people tell me to stay with NGK Copper plugs so I did. Everythings seems ok, but I've never been able to clear that initial ka-clunk spark knock type sounds when first starting it.

 

[seeless85]

I changed the plugs this morning. I did go with the NGK copper plugs. I noticed the gap on the old plugs was almost double that of the new ones because of wear. So far the car seems to start better and have a little more power. No more service engine light as of now, but the new plugs have only been in for a couple hours and I only took it up the road once for a test drive after the service. Hopefully this solved the problem, I'll keep you posted.

 

[seeless85]

Just an update.....so I changed the plugs on the fourth of july and so far the engine light has not come back on. For what its worth. Not sure if its coincidence or if the plugs really cured the problem. Thanks all for your help.

 

[jaredhall]

Our '08 patriot has had an intermittent service engine light since this winter. We assumed a loose gas cap as it would go away after a while. My wife took it to autozone and they said it was an oxygen sensor. About 2 weeks ago we had it inspected (passed emissions test) with no issues. The guy at autozone couldn't believe that the car passed inspection with an O2 sensor problem, but the light wasn't on then either.

So my question since I haven't ever really worked on the Pat yet is, how many O2 sensors do we have? Is there any way I can tell which on it is without bringing it to a dealer with more sophisticated equipment and a charge? How hard is an Oxygen sensor to replace? Are there any tricks I should know? The car has about 34,000 miles on it and is due for spark plug change also. I have them I just haven't gotten around to putting them in. Could a faulty plug cause an O2 sensor to trip the service engine light? They erased the code at autozone and it hasn't come back on in two days.

The car has the 2.4L with cvt.

Thanks in advance for the help!

I know im late with this but just a follow up question. Im on the same thing a month ago until i come up with this late thread. On my patriot, there is a leak on the pan and just wondering what would be the possible price of the repair in US countries. I got a qoute from a shop but just wanna see and compare if this is fair enough.

 

[rnrpfx]

Engine Light - oxygen sensors

I have same type of issues...I have a 2008 Patriot Sport 4x4 that I have had for approx 5 months now. The oxygen sensor on top of the engine was replaced 2 and a half months ago. Driving locally is no issue, but when I hit the highway, the engine light comes on in and around the 150 to 250 KM mark and will not go off. First off...how many oxygen sensors does this Jeep have?....also....if there is 2 of them....is it possible the other one needs to be replaced?....HELP!!!!!!!.....getting tired of this engine light stuff............

 

[todde702]

There are two. A pre and post cat sensor. Get the code(s) pulled from a parts house and post back. We couldn't even begin to guess an issue without the codes.

 

[sp00ge]

I've been having the same issue for the past 6 months, where the light would intermittently turn on for a day or two and then stay off for a week or so. But for the past two months, the light has stayed on. The only code pulled was the generic 0420, which means a problem with the cat (or, hopefully, just a faulty downstream o2 sensor).

I just picked up a new sensor the other day, and am going to try to get it swapped in today, as long as the weather stays nice. I'll update later.

 

[2K7]

Someone told me don't use the Bosch sensor, is this true? Also do you think I should just go straight for a mechanics diag instead of just swapping the downstream sensor after the cat?

I'm getting these error codes now so close to emissions I need to get it resolved ASAP.

P0139 O2 Sensor Circuit Slow Response Bank 1 Sensor 2
P0420 O2 Catalyst System Efficiency Below Threshold Bank 1


I just replaced my brakes and alternator myself, when it rains it pours (money out of my wallet).

-Adam

 

[Terasec]

Someone told me don't use the Bosch sensor, is this true? Also do you think I should just go straight for a mechanics diag instead of just swapping the downstream sensor after the cat?

I'm getting these error codes now so close to emissions I need to get it resolved ASAP.

P0139 O2 Sensor Circuit Slow Response Bank 1 Sensor 2
P0420 O2 Catalyst System Efficiency Below Threshold Bank 1


I just replaced my brakes and alternator myself, when it rains it pours (money out of my wallet).

-Adam

with P0420 there is no definitive way to tell whether its 02 sensor or cat convertor
i had p0420 for years, changed sensors didnt help,
eventually i gave in and changed the cat con,
fixed my problem/light but doesnt mean thats the case everytime for p0420
even dealer told me they cannot narrow down code to sensor or cat,
and to try the cheaper option first
screenname as in 2007?
there is also a seperate warranty for emmissions, dont recall if its 80k or 100k miles
i would check if your emissions warranty is still in effect

 

[festerw]

Someone told me don't use the Bosch sensor, is this true? Also do you think I should just go straight for a mechanics diag instead of just swapping the downstream sensor after the cat?

I'm getting these error codes now so close to emissions I need to get it resolved ASAP.

P0139 O2 Sensor Circuit Slow Response Bank 1 Sensor 2
P0420 O2 Catalyst System Efficiency Below Threshold Bank 1


I just replaced my brakes and alternator myself, when it rains it pours (money out of my wallet).

-Adam

For some reason the Bosch sensors don't play well with Jeep computers, I've had problems with them myself. The last ones I replaced I used NTK sensors and haven't had any issues.

 

[KCab]

There are two. A pre and post cat sensor. Get the code(s) pulled from a parts house and post back. We couldn't even begin to guess an issue without the codes.

I am having the same issues; Codes are P0139 for O2 Sensor and P0420 for CAT

Please help... thanks!

 

[HectorNidaho]

I've been having the same issue for the past 6 months, where the light would intermittently turn on for a day or two and then stay off for a week or so. But for the past two months, the light has stayed on. The only code pulled was the generic 0420, which means a problem with the cat (or, hopefully, just a faulty downstream o2 sensor).

I just picked up a new sensor the other day, and am going to try to get it swapped in today, as long as the weather stays nice. I'll update later.
@sp00ge - Did you replace the sensor and did it resolve your issue?

 

[HectorNidaho]

@sp00g - Did you replace the sensor and if so, did it resolve the issue? I am having the same issue with my 07 jeep patriot.

 

[LouOfTheJeep]

If you go on NGKs website and check which plugs are compatible with the Pat there are several listed. All are copper plugs (this refers to the core and not the coating on the electrode). You can put in platinums if you want and won't have any problems. Just make sure that the gap is correct and that they are compatible. If someone used a platinum tip that had a problem than it is likely that the plug was faulty or not gapped correctly. Just keep in mind, that even if platinum plugs are installed, you should still pull that at the recommended intervals and re-gap/clean the plug. This ensures that they will not seize in place and that the gap will stay within spec.

Also, OE sensors are NGK, so I would stick with those if possible. They are a good quality and aren't expensive, so there isn't really a need to go with something else