Hi i'm the new guy. Want to run some check engine codes by you guys

#1
And see what you think. Any constructive input would be appreciated. About a month ago jeep was stuttering or hesitating 3rd thru 5th low end of gear. Engine light came on. Got p0430. I put some gas treatment in. Jeep ran smoother i reset the computer, and a day or two later i got p0455. I bought a new gas cap hoping it would fix it cheap. A couple of days later i got p1129 and it started stuttering again, but then it quit but reaction was crappy.Thats been an intermittant code for a week or so. Was going to take it to galeana today but the light went off again. How do these codes relate. I think it could be the catalytic converter, but i was wondering if that was the first time i ever put gas treatment in( i only have 28000 something miles on it) could it still be gunk or something burning through causing the codes. The light hasnt come back on today and it seems to be grabbing gears alot better. Its a 2010 wrangler sport. Thanks
 

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#2
FYI before you take much of what I say with much weight, I'm a noob when it comes to the computers in these things. These are just observations from researching the codes. Others on the site will be able to elaborate a lot better than I can.

Both the first code (P0430) and the last code (P1129) could be related to the O2 Sensor. The second code is kind of a strange one to pop up and you may have taken care of that one with the gas cap. I did see that a physically damaged cat can cause an O2 sensor to burn out and send bad signals. Have you taken a good look under the Jeep to see if anything is physically damaged?
 
#3
i have no idea what the code #s mean but theres usually a description that goes with em if somebody could get us those it would be alot easier, that being said, with only 28k why not just take it back to the dealer and have what ever it is fixed under warranty?
 
#4
I was going to take it yesterday but the engine light went back off. Wanted to mak e sure they had something to go off of. If they don't find anything wrong they charge you 60 bucks for just looking at it. I think the O2 sensors have there own code, i could be wrong though. I did look underneath. Everything looks ok to me. Thats not saying to much though really.
 
#5
So you have a 430, 455, and 1129 codes.
430 is catalysts below threshold bank 2
455 is evap system large leak detected
1129 is fuel system closed loop not achieved
They are all hand in hand!
Possibly a single cause for all 3 codes?
Fuel restriction, vacuum leak, failed O2 sensors, failed converter, evap system leak. The fuel and emissions systems are directly related, and best properly tested, repaired by a professional. There are lots of possible causes for your issue, and I only threw out a few that are more common. You need someone that has the equipment, and training to repair it properly. There are several expensive options that may do nothing more than hide the true problem for a period of time!
 
#7
I'm asking probably a stupid question because i really really hope it's not what it is. Could it be possible someone put something in my gas tank and cause those codes. It ran fine today, no engine light all day with 3/4 tank. It seems to me it all happens when the tank is 1/4 full or less.
 
#8
The MIL, or check engine light is triggered by 2 consecutive cycles with the same fault. It will go off with 4 cycles of proper operation, but still stores the code in memory.
It's not likely that your fuel was tampered with. Contaminated fuel in most cases will cause not only poor economy, and MIL, but the engine will run horribly rough.
 
#9
Like it was mentioned above the 430 and 1129 codes would indicate something wrong with the O2 sensor/catalytic converters. With this being said, in my OBD2 diagnostic experience, the codes don't always point directly at the problem. In fact, most of the time they haven't in my experience. If you're saying the codes mostly happen with 1/4 tank of fuel or less, I may suggest you have the fuel pressure tested. Fuel pumps can act funny when they get too hot and this problem usually pops up when there is low fuel in the tank. Fuel pumps can overheat themselves fighting against a clogged fuel filter, so maybe check that as well. It's really hard to diagnose some of these codes because everything interacts with everything else. I attended a guest lecture at ICAR a while ago specifically on this topic of diagnosing these complex systems. The systems are already so complex that even with these codes, the easiest way and sometimes the only to diagnose a problem is to replace parts until the CEL goes away, and that's exactly what the dealerships do; sometimes they really don't have any other tools at their disposal. Only after they gain experience with what fixes a problem, will they know what to go to first the next time they see it.
 
#10
Cool, thanks for all the help guys. It puts me at alot more ease to think someone didnt put something in my tank. i did get a locking gas cap when i replaced the old one, but still. It's really weird that it seems to be running fine for now. I've been getting on it a little harder just to see how it runs and sounds at higher rpm's. Could it be that the other codes stemmed from the 0455 code and after i got the gas cap it just took a few days to regulate back out, or is it for sure the cat converter or the o2 sensor
 
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