Help with OBD P0158 & P0162 Codes

[Mr.Paul]

Help with OBD P0158 & P0161 Codes

Greeting. 2004 Liberty, 3.7 6 cylinder with 62,000 miles. New platinum plugs, oil change, pcv valve @ 60,000. Shortly after purchase of this vehicle at 60k and a solid pass at the smog station, the OBD started kicking up a P0158, which is a o2 sensor, bank 2 downstream (passenger side after cat).

After purchasing a new sensor and replacing it, no luck and same code. To ensure that the new sensor was not bad, I removed the driver side sensor downstream and used it in place of the passenger side sensor. Same results after resetting the computer. (battery disconnected for 30 minutes).

Can of SeaFoam in the gas tank. No change. Then magically 500 miles later, light went off. Light off lasted several days and now it is back on and kicking up the P0158 code with a new code also, which is P0161.

Is this an injector issue? Engine seems to run okay with no noticeable problems. I have been tracking gas mileage and libby is getting 17mpg average. I did read somewhere that the libby's like copper plugs, not platinum. Could this be a problem?

Any ideas before I have to mortgage the farm and take it to the Jeep dealer?

Thanking all for reading and possibly responding.

Paul

 

[isomswim]

Greeting. 2004 Liberty, 3.7 6 cylinder with 62,000 miles. New platinum plugs, oil change, pcv valve @ 60,000. Shortly after purchase of this vehicle at 60k and a solid pass at the smog station, the OBD started kicking up a P0158, which is a o2 sensor, bank 2 downstream (passenger side after cat).

After purchasing a new sensor and replacing it, no luck and same code. To ensure that the new sensor was not bad, I removed the driver side sensor downstream and used it in place of the passenger side sensor. Same results after resetting the computer. (battery disconnected for 30 minutes).

Can of SeaFoam in the gas tank. No change. Then magically 500 miles later, light went off. Light off lasted several days and now it is back on and kicking up the P0158 code with a new code also, which is P0161.

Is this an injector issue? Engine seems to run okay with no noticeable problems. I have been tracking gas mileage and libby is getting 17mpg average. I did read somewhere that the libby's like copper plugs, not platinum. Could this be a problem?

Any ideas before I have to mortgage the farm and take it to the Jeep dealer?

Thanking all for reading and possibly responding.

Paul

Code P0161 comes up as low voltage. Not to insult inteligence got a couple questions though.

Sure you have the right O2 sensor?
Only Seafoam in gas tank?
Is there any type of idle fluctuations? Loss of power while sitting?
Strain on battery? How old is it? Is it ground well?
Did you change plugs? Proper torque settings?

Idea. Attempt to clean the valves by doing a thorough Seafoam clean. Just look for vids on it in youtube should be some.

 

[Snail Farmer]

What brand was the new O2 sensor? If you didn't get NGK, I would replace it with an NGK before you do anything else. I just went through a lot of trouble with my liberty, and spent a lot of money replacing things with no improvement. As soon as I put NGK O2 sensors in, it ran beautifully and haven't had a problem since.

 

[rockymountain]

What brand was the new O2 sensor? If you didn't get NGK, I would replace it with an NGK before you do anything else. I just went through a lot of trouble with my liberty, and spent a lot of money replacing things with no improvement. As soon as I put NGK O2 sensors in, it ran beautifully and haven't had a problem since.

NTK actually right?

More Information for NTK 23135

 

[Snail Farmer]

yes they are actually NTK, but if you go to a parts store they're labed as NGK. I actually got into an argument with the guy at NAPA over that. 23135 are the pre cat sensors and 23132 are the post cat sensors

 

[rockymountain]

Hmmm. Interesting.

 

[MidSouth Mitch]

I'm trying to help a friend find out what's going on with his '04 Liberty 3.7 with 169k miles. Recently had the head gaskets replaced (8K miles ago). A few days ago, the power fell off a cliff while driving at 65mph- Felt like it wouldn't pull a greased string across a sheet of Teflon! Then it shut completely off. It started when re-cranked and barely made it home. Now he noticed it loses power as it achieves normal operating temp. Sitting idling, it will slowly drop rpm until it finally shuts off. He's changed the TPS, IAC, O2 sensors, spark plugs, coils, EVAP purge solenoid and PCV valve- All to no good effect. Rather than throwing more $$$$ at it...What next would anyone advise to check? Please advise. Thank you!

 

[teeje]

I'm trying to help a friend find out what's going on with his '04 Liberty 3.7 with 169k miles. Recently had the head gaskets replaced (8K miles ago). A few days ago, the power fell off a cliff while driving at 65mph- Felt like it wouldn't pull a greased string across a sheet of Teflon! Then it shut completely off. It started when re-cranked and barely made it home. Now he noticed it loses power as it achieves normal operating temp. Sitting idling, it will slowly drop rpm until it finally shuts off. He's changed the TPS, IAC, O2 sensors, spark plugs, coils, EVAP purge solenoid and PCV valve- All to no good effect. Rather than throwing more $$$$ at it...What next would anyone advise to check? Please advise. Thank you!

Hook up a scan tool. Check the throttle plate and make sure it's not getting stuck from carbon deposits. Wouldn't hurt to test the battery and alternator too while you're at it.


2002 Jeep Liberty 3.7L with brand new engine
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