crimsondragon
NAXJA Forum User
- Location
- NJ
Brief history of what's happened so far. About a month ago, The jeep threw a code for PO138 which is an O2 sensor issue. I took a look underneath and found that the area where the hanger was welded that mounts to the crossmember has cracked all the way around and my exhaust was just sitting on the member with a giant hole in it. I decided it was salvageable so I welded it up. Not the best weld job as there are some leaks but it does the job. In the process, I replaced the catback with a Flowmaster 44 and a 2.5" pipe. I also decided to replace the rear O2 sensor with one I bought from rockauto: ULTRAPOWER SG1815. A day later I installed a set of used Precision injectors. I drive the jeep everyday and within the last month I easily have put maybe another 1k miles on it.
Fast forward today, I get the code PO420. Well the cat I'm pretty sure is factory stock and when I took it out to fix the downpipe, the honeycomb was intact and I could see through it. Also, this past Saturday I took it to get NJ state emissions test and she passed but I didn't get a spec sheet so I have no idea what the readings are. This jeep has CA emissions package as stated on the build sheet. My initial thought is that the rear O2 sensor crapped out. I've never heard of Ultrapower before but figured I'd give it a try. I don't think it's the cat since it looked fine and it passed emissions. The inside of the new pipe is still clean. No soot so I don't think it's running rich either. She idles fine, gets good power and a mpg of about 21 combined although since the exhaust and injector install, mpgs seem to have suffer a tiny bit but that might be due to me driving it more in traffic than before.
The only other threads I found with this code refers to some recall where the dealership reflashes the ECU. I haven't been there ever so that's not the case. Thoughts? Thanks for any help in advance.
Fast forward today, I get the code PO420. Well the cat I'm pretty sure is factory stock and when I took it out to fix the downpipe, the honeycomb was intact and I could see through it. Also, this past Saturday I took it to get NJ state emissions test and she passed but I didn't get a spec sheet so I have no idea what the readings are. This jeep has CA emissions package as stated on the build sheet. My initial thought is that the rear O2 sensor crapped out. I've never heard of Ultrapower before but figured I'd give it a try. I don't think it's the cat since it looked fine and it passed emissions. The inside of the new pipe is still clean. No soot so I don't think it's running rich either. She idles fine, gets good power and a mpg of about 21 combined although since the exhaust and injector install, mpgs seem to have suffer a tiny bit but that might be due to me driving it more in traffic than before.
The only other threads I found with this code refers to some recall where the dealership reflashes the ECU. I haven't been there ever so that's not the case. Thoughts? Thanks for any help in advance.
