Hey guys did a day trip to Florida from ATL, Georgia last weekend(8 hours) round trip and got the code as I was heading back in. I stopped at a parts store and reset the code and it came back about 160 miles back on the HWY.

Car didn't perform different so just did the speed limit and made it back to ATL and reset ...

Next day drove down the street to the detailing shop but hasn't came back on yet.

Anybody ever get this code? Advice on next steps?

Thanks in advance

 

Going from memory, the P0173 is the car reading the outflow as too lean, meaning excess air, so it compensates by running richer (higher fuel). Look for air intake leaks after the mass air meter. It could be the other way around, lean/rich rich/lean compensation, but rarely a serious issue.

 

@davidmaria1 Thanks for the reply!

 

Usually means there is too much air in the air/fuel mixture. I would definitely check it out, as long term lean mixture can cause other issues (like killing the Catalytic converter over time). Most likely some unmetered air is entering the intake system somewhere... A leak somewhere letting to much air into the mixture. Could also be a stuck/sticking injector (not enough gas getting in and thus too much air in the mixture ratio).

I would start by looking for air/vacuum leaks.

Good luck.
DC

 

Took it to an independent shop and got this reply:

Initially we monitored fuel trims for both bank 1/2 for short and long term fuel trims. After 10 minutes we found no data to confirm air/fuel ratio imbalance or intermittent failure of the oxygen sensor. We removed oil cap and found strong fuel smell within the oil indicating excessively high oil mileage or fuel leaking into the crankcase. We reviewed oil service life and it shows a recent change, but history shows 12,000 miles since last oil service. We decided to remove a spark plug to inspect combustion burn quality and found high traces of hydrocarbons on fire ring while ground strap shows proper burn ratio. While idling we found rough running but no active misfire or trouble codes. We believe the high pressure fuel pumps are failing and leaking fuel internally into the crankcase. Having erratic fuel pressures and excessive fuel into the crankcase (which burns through the exhaust as unmonitored fuel) is causing this fault to occur. As the repair requires removal of the subframe

They want to charge $2,825.84 for the work.







@Therock88 @davidmaria1
thoughts?

 

Seems high to change plugs and pumps. Hard to read their estimate though. Also, if too much gas is leaking INTO the system, it would seem to create a rich mixture, but your code is for a LEAN mixture?

DC

 

Is the rough running a new condition? No new codes seems odd. Not questioning the abilities of the mechanic, but fuel smell and 1 plug seems like light evidence for $2800. I'm not clear as to where the excess fuel could be added, without any evidence. I think the pumps are shaft driven, like an old style valve.

 

Yeah it wasnt running "rough" when I was driving it, and there are no codes being thrown. Im not at the shop yet. Going to tell them to hold off and maybe take to a second shop. Keep in mind the (P0173)code isnt throwing now. It threw more than a week ago...I just wanted them to check out the car.

 

Drive it. Change the oil/filter. Drive it. And just to be safe, disconnect the negative terminal for a couple minutes to take the car out of diagnostic mode so the battery doesn't drain.

 

Yep...going to pick it up today after work.

 

Did this code ever come back for you?

I just picked up a 2017 and drove it across the country. Got this code three times, the first time after 500 miles, reset and came back at roughly 1000 mile intervals. All three times I was in dynamic mode with the exhaust open, and the last two times I was at high elevation, like 6,000+ feet.

Car never ran rough or did anything other than perform flawlessly, I reset it when I got home last night and will monitor now that I am done with long trips in the car but just thought I would check to see if you ever had any more issues or discovered the culprit.

 

Hey MCMike, what was the problem, and how did you fix it. I’ve had the exact same problem. Fault codes: P0173-00 and Р0089-64.
The dealership reccommended to change fuel pumps.

 

Any updates?

I am having the same code on a 2018 35t, 3.0.
took to dealer and they charged $400 and said that it appears to be a vacuum leak and a smoke test is required…then they quoted $500 to do that. We have been driving it with the CEL on for months, but inspection is due so it needs to be corrected.

I bought an inexpensive smoke machine to try out myself…and am going to replace the air filters and possibly the MAF- it runs too darn well, can’t see how it could be fuel pumps or injectors…oil change is almost due so I will do that as well. Light came on at 58k miles. We have 63k on it now.

 

Sorry, missed your request here and sadly don;t have a good update for you as after another roughly 20k miles I have not had this code again.

 

Well, thank you for replying. I will try the smoke machine and see where that gets me. I also need to figure out which is the best obd2 machine for this car.

 

New member here. I have a 2017 F Pace 35t Prestige, 91k miles and the check engine light came on during a road trip and the fuel tank started dropping like a stone. Filled it up, no apparent leaks, nothing apparent under the hood, took it to get it checked and got the P0173 FT Bank 2. The guy at the parts store said it was likely a faulty O2 sensor. Lately my car has been in the car so much for hoses and alternator issues and random things that my warranty company actually said I'm out of coverage funds. Any suggestions?