forayzor 1 Posted July 11, 2012 I would replace the coils. Not very expensive and they may be the result of your intermittent misfire. the o2 high voltage is probably a result of the misfire. Heater circut most likely has nothing to do with your how its running and I wouldn't worry about it unless you notice a problem with the HVAC. The high volt charging code is probaby a fluke or something related to the power to the coils possibly not being very sound... clear it out and see if it comes back Recommendations like this are why you should take the vehicle to a dealer or reputable shop. No one on here can give you an exact diagnosis just by going off your dtcs. A tech has been giving you the best advice so far, but even he (and I) can only guess without putting our hands on the car and doing tests ourself. My best guess would be a wiring issue, whether a ground, short to power, or open circuit. Quote Share this post Link to post Share on other sites
Murphy4570 15 Posted July 12, 2012 Recommendations like this are why you should take the vehicle to a dealer or reputable shop. No one on here can give you an exact diagnosis just by going off your dtcs. A tech has been giving you the best advice so far, but even he (and I) can only guess without putting our hands on the car and doing tests ourself. My best guess would be a wiring issue, whether a ground, short to power, or open circuit. Oh wow I missed that guy's post LOL. One question I have in regards to the OP's situation: Has the CEL been on for a while, or did it just come on very recently with all of these codes in memory? My previous recommendations were based on the codes just piling up from the vehicle being ignored and lack of maintenance concern, which is what most people do. If the CEL just came on yesterday, then that is a huge red flag. Quote Share this post Link to post Share on other sites
raz-0 1,259 Posted July 13, 2012 When an OBDII computer reads a misfire on multiple/random cylinders, it will not set a code for an O2 heater circuit, or a O2 high/low voltage. It could set a code for being too rich since the cylinder isn't firing, and is still injecting fuel. Circuit/voltage codes are specific to just that. Op said he had bad gas, and is still having sputtering on decel. Could be his o2 sensors are fouled, some cars will throw a bad heater circuit code for a slow sensor out of spec (my current one does), some won't ( my last one, early obd2 car, didn't). Also could just be the coil pack going bad and too much unburned fuel hitting the exhaust system and fouling the sensors. Except for the over voltage code, they all could be due to a chain of events of a degrading coil pack. Quote Share this post Link to post Share on other sites
XDJohnTact 49 Posted July 13, 2012 I hope the OP will revisit this post and let us know what the resolution to the problem was? Interested in seeing which one of us armchair mechanics guessed it right? Quote Share this post Link to post Share on other sites
djg0770 481 Posted July 18, 2012 Update required!!! Quote Share this post Link to post Share on other sites
NJJim 37 Posted July 18, 2012 I missed this post before but would like to add my .02. Take it to a reputable repair shop or dealer. You could get lucky trying one of the suggestions here or you waste hundreds of dollars. Why not let a real mechanic diagnose the problem and be done? Quote heard at service counter "I already spent $300.00 at the zone and gave my brother in law $600.00 for new coils and fuel pump, so I don't think its right for you to charge me $125.00 to find out whats really wrong." He probably believes everything Obama says too. Quote Share this post Link to post Share on other sites
BD104X 1 Posted July 18, 2012 Im also for taking it to the dealer or a legit repair shop. Doing brakes or some maintenance work yourself is one thing, but todays cars are complex and guessing and throwing parts at it gets expensive fast. Not all dealers & shops are thieves. Most will only charge you a diagnostic fee if you opt not to have the repair done and you only use them to tell you what's wrong. You could spend hundreds on parts only to find out that the problem is a re-flash (software update) to the ECM and you had to go to them anyway. I guessed and put coils in my Chevy Trailblazer that didn't fix it, it turned out to be a cam timing oil control valve and the dealer charged me $250 and I was on my way. I work in the parts department at an Audi dealer, and so i see people guess and buy parts they cant return all the time. Yes, our service department is s bit more expensive than your average shop but we're honest and stand behind our work. Quote Share this post Link to post Share on other sites
XDJohnTact 49 Posted July 19, 2012 Seems all the "pro's on this site are singing the same tune? Take it to the dealer! I guess if I was "in the business" I would be recommending "taking it to the pros" too, but that was not what the OP was asking (although he seems to be mia lately). I have been driving for going on 50 years and I have never paid a mechanic/dealer to fix any of my scores of cars, motorcycles or boats. Just my .02 Quote Share this post Link to post Share on other sites
BD104X 1 Posted July 19, 2012 Seems all the "pro's on this site are singing the same tune? Take it to the dealer! I guess if I was "in the business" I would be recommending "taking it to the pros" too, but that was not what the OP was asking (although he seems to be mia lately). I have been driving for going on 50 years and I have never paid a mechanic/dealer to fix any of my scores of cars, motorcycles or boats. Just my .02 We are just trying to give him advice, just like you. To be honest, it seems to me that this guy has a list of codes and doesent know where to begin, and that it usually the guy who wastes the most money by guessing. Besides, I work in the parts department, so I make money whether the customer fixes it or the tech does. In fact, if he mis-diagnoses it, I make money on the parts that didn't fix it too! You sound like a pretty capable DIY'er and i applaud you, but you are a rare breed. I wish I had a dime for every time I saw someone buy a air flow meter because "Autozone checked the code for me" only to find out the rubber boot from the air cleaner to the throttle body was split. You would probably come in and buy a relay because you checked it with a volt meter, but 90% of the time its because the customer "heard it clicking" and it doesent fix anything. No offense to the OP, but I have a feeling the reason why we havent heard from him is because he wasn't really looking for diagnostic help but hoping to get an easy answer like "common problem, just replace the XYZ sensor". It's worth a shot, but unfortunately it usually doesent work out that way, but I see it every day - hence my advice. Quote Share this post Link to post Share on other sites
XDJohnTact 49 Posted July 19, 2012 I was a night manager for a parts store for 13.5 years so I know what you mean. Quote Share this post Link to post Share on other sites
M4BGRINGO 139 Posted July 19, 2012 Lots Of good advice above, jeeps are pretty easy to work on. If it comes down to you needing a new fuel pump, I have a spare in my garage for a jeep tj Not my neighbors Grand Cheroke! She had a squealing noise one day, I took a quick look, the serpentine belt was smoked from a seized water pump. I did the job for her and HATED IT! Should have pulled the radiator. My hands got sooooo cut-up from that thing trying to get the fan clutch off, what a royal pain! Got some really good bottles of wine outta the deal though. Quote Share this post Link to post Share on other sites
