P0171 on a 1998 Dodge Stratus

At this point I am guessing an intermittent electrical wiring problem with the O2s. I hope after four days with the car that the Dodge dealer checked for your suggestions. I know Bosch is not OEM, but I can't imagine with their range of experience that their aftermarket stuff can be that off. If I can't find a problem with the wiring (dirt, pulled connection,etc), I will try replacing with OEM O2s. My Dodge dealer stepped up to give me 10% off to throw money their way for a problem they can't figure out on one of their own cars (OEM vs aftermarket). And they wonder why the Japanese are giving it to them in the a$$ every year.

I recently replaced the fuel pump assembly ( pump, regulator, fuel tank level)> The regulator did not read properly for a few years ( mostly correct, but sometimes reading 1/4 tank and running out of gas). Used fuel mileage to avoid standing on the side of the road. Recently the pump stopped working so changed the whole assembly which included the pressure regulator. Have not checked the pressure,but doubt both regulators where off ( and hope Dodge checked this during the week they had it). I feel vindicated that my troubleshooting skills are above minor league with the Dodge dealer giving up, but I would trade all of that just to find the answer and move on. So if anyone out there has experienced an out of the ordinary solution to this error code, chine in, please.

Don't assume that all dealers are as competant as that one. Don't paint me with that brush. There's are at least sides 2 every to every story and yes you're entitled to your frustration but just because they didn't find the issue with your car doesn't mean you're as competent as there techs with diagnostics. If you were you wouldn't be here or there would you. Enough with that kind of foolish talk. Alot of people yank those codes, drive over to the "zone" and buy those pos bosch sensors screw them in and when the codes are still there figure the diagnosis was wrong. It may be a correct one but your parts choice let you down. If you go to the dealer and say I want the diagnosis done but Im not going to pay you guys to change the parts because I can do it as well or better then newsflash they probably aren't going to find the problem. O2's are a good educated guess but as soon you say that to a customer like you who can change them out he's going to demand his money back when it doesn't pan out so of course they may suspect the 02's but you're not going to committ to them whether they fix or not so they won't commit to the diagnosis either. Too many buy the correct parts, get a mouth full of crow and keep it shut instead of admitting it they wasted so much of there time and money farting around with the kids at the zone playing johnny wrench! Without knowing how much time they spent on your car and what exactly they checked we can't condemn them or commend them without there side of the story. In my dealer if I got your car in and it had that many parts changed and an ongoing issue like that one that required that many parts to be rechecked and that much seat time on test drives you'd be up in to the 4-5 hr range of diagnostics in no time over a 4 day period which is into the 400-500 dollar price range on the ro. If you're bill isn't up there then you've really got little to whine about. Lots of parts that cost under a 100 bucks cost at least that to diagnose so it's very rare that a customer with 400 bucks to spend chooses to spend 300 dollars of it on diagnosis. Evap dtcs are a perfect example. 20 dollar cap. 100 bucks to prove it's leaking. Lots change everything before paying for the smoke test because they always feel better with new parts. It's the nature of the business and always has been. You're not in the business so don't run down guys like me who are! This site isn't for that never has been, never will be. I'd either start with putting proper 02's into it, smoke testing the intake to check for a vaccum leak and pressure testing and flow testing the fuel pump. I imagine you're equipped to do the first of the 3. The other 2 will require a shop or some tool purcahses and knowledge on your part to execute properly.

The reason I didn't feel it was related to fuel supply was because he said the vehicle was "loading up" and two plugs were fuel fouling. Using this, I suspected that the P0171 was overfueling two cylinders to compensate for a lean in the others. Fuel pressure would affect all, however it doesn't rule out clogged injectors.

Jeff, don't take my disappointment with my local dealer as bucketing all techs. Just as there are good and bad engineers. So I think I found the problem. Since it seemed like an intermitant problem bringing in the code, I started chasing the wiring. Earlier in this endevor I checked the connectors and they looked good. Discover more Dodge Ram 1500 fuel Ram The wiring for the pre-cat O2 sensor has about a 10 inch run up to a larger wiring loom. This 10 inches has a cloth type material. Anyway, I cut this outer cloth back to find a junction to test continuity through the connector. When I did I found the insulation for all four wires to have disolved into pieces (chunks). The wiring further up in the loom was fine. I rewrapped the wires and the car runs great now. Too bad Dodge did not do an FMEA for the O2 sensors for when they fail open, closed, or short. Maybe then the dealer's techs would have the info in a service bulletin. Thanks everyone for trying to help. Hope this info is of use in the future.

Helo Does the engine code P0171 is nomore displayed ??? Are you sure ?? How many trips passed since you clear the codes?? I´m impressed these wiring problem fixed the code ¡ I can´t imagine why you didn´t get another O2 sensor code instead the P0171, if there has been a wiring problem it should had got another different code like for example: P0130, P0131, P0133... but it could be. And scann again your car after more driving trips. Keep posted

That's a very common spot for wiring problems on those cars. It would have been one of the first places I'd look because I've seen it before. Suprised they didn't check there but again 2 sides right ! gotta ask though FMEA? means what?

Failure Mode and Effects Analysis. A basic for all mechanical systems. Since the O2 sensor is a 4-20 mA signal, the computer should have been programmed to list an open contact possibility at either of the extremes (4 or 20), but definately for 0 mA. As the dealer said, the problem was intermitant so I suspected wiring. I had checked my connections numerous times before. I only decided to chase the original wiring (that no one has fiddled with) as a last resort. Found the obvious smoking gun. The car passed the smog test today. Jeff, if you have seen this before, why didn't you mention it? That was the help I was looking for.

I'd imagine from my experience that the wires for the 02 never went totally open to the pcm but just had prolonged high resistance. Im sorry I didn't think of that splice issue sooner and mention it but If I listted and remembered everything I've seen it would be a whole page everytime, not bragging just saying I've seen so much nothing suprises me anymore. That wiring spot tended to show up as more faults with ignition drivers but Im sorry I didn't mention it sooner. It wasn't my intent to be malicious if that's how you took it. Often with intermittents like yours I run new wires for the circuit I suspect instead of openning up harnesses. Too many times more problems are created by people hacking at looms with razor baldes then ever get solved. good on you for finding it. A scope would have cut your diag time down considerably because the signals then become visual instead of a calculated average in a pid! Again sorry I didn't think of it or mention it! I normally tell everyone to recheck circuits after parts have been swapped out to no avail. Ah well just think of the mileage you're going to get now!