Once in a while I get a PO171 code. Car run fine, so I see the reason, and put it out. Replaced map air , and two Bosch upstream sensors. Light still comes on once In awhile. Brought to dealer, and they say with those 02 sensors they don’t see voltage change like they should. Can’t find oem sensors, and is this really the problem or a process of elimination. Thanks I’m advance for your help. John

 

John The only help I can offer for you is NEVER TAKE THE CAR TO A DEALERSHIP AGAIN! That being said, if you look up the code here, you might be able to help yourself by searching the forum for ideas. Knowing the DTC error doesn't necessarily tell you what or where the defect is. It'll only 'point' you in a direction to help determine the defect(s). Absent that, someone else might chime in to help. As a footnote, what did the dealer rip you off (in dollars) for the 'diagnosis'? Hopefully, they didn't (also) soak you for more before you took the car out of their guesswork bay. Good luck!


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Not even sure if the problem is with new Bosch 02 sensors , as the dealer states. He said to go any further I need oem sensors that aren’t even available. When light comes on ,car runs fine. Love the car, but PO171 driving me crazy. Someone please help . Thanks

 

OEM sensors are not required, they are just off the shelf sensors in a plastic bag with a Chrysler part number on them with a horrendous markup, something like 100%. There is no benefit in paying twice the price for something as it will not magically solve the problem.
This forum probably has the answer to your problem somewhere.

 

Chrysler tech showed me that when vehicle was running, he wasn’t seeing the sensor voltage changing as he said it should.

 

What brand of maf sensor and oxygen sensors did you install?

 

They were Bosch. I’ve noticed that when I take a slow uphill turn to the left or right, sometimes the car will bog down like it wants to stall but then clears up. I’m wondering if my problem could actually be a fuel filter .

 

Well Bosch is the original manufacturer of the MAF and oxygen sensors. Were the oxygen sensors the correct ones for the SLK320/Crossfire? Upstream are Bosch 16167 and downstream are 16276. I searched on Google and it could be a vacuum leak somewhere or even the downstream oxygen sensors. The fuel filter has a built in regulator and there is a port on the right side of the engine where you can check the fuel pressure. Probably best to take it to an independent shop that specializes in German cars versus throwing parts at it and guessing.

 

It doesn’t seem like an easy one to diagnose. I would have thought the car would run poorly, but it runs fine. I’m at a loss on this one, when the dealer won’t go any further until it has oem 02 sensors that aren’t available

 

If you fall for that BS then you will pay through your nose. First because he has made an excuse for not finding the fault, if he did find some OEM injectors you would have the same problem but you would pay for the sensors plus labour charges and get nowhere.
There is nothing special about the original sensors they are the same as the equivalent’s you can buy over the counter.

 

They are 02 sensors, he was talking about. It would be really helpful if there was a device that could actually pinpoint the problem.

 

Sorry sensors, I was thinking of another thread I was posting to, but sensors or injectors and all these type of peripherals are made for many vehicles are sometimes put in a plastic bag with an auto makers name on it and it is suddenly worth more if you want to buy it.
Here are a list of possible problems causing the P071 code. The car is running lean, driving it too far could cause damage by burning valves etc.
Check for sufficient fuel pressure first.

 

U could have a NEW BAD sensor swap from left to right and see if u get the same porblem but on the other side then replace that sensor jim
or if u have old sensor then use that one to replace the one giving u a code

 

Thanks, but I wonder if it’s another issue setting off the code other than the 02 sensor. That was the same code prior to me having them replaced.