dc5itr888

Just came home from some spirited driving and noticed that my CEL ( Check Engine Light) was on. I have no idea when it came on but pretty sure it was a few miles right after I purchased gas.

I have a OBD II reader and the code is P0171. I researched it and I believe some people here were saying its a bad tank of gas? And a bunch of other various things. But Im sticking to bad gas since I literally just bought it and not long after I have the CEL.

My question is if it is how do I get the gas out ? I only bought 3.159 gallons of it.

I have a third party warranty ( AAGI) hopefully they will cover this.

thanks

dc5itr888

My car is also bone stock, read that most people with P0171 have diff filters, charcoal etc.

Mort

Put some known good quality gas in and clear the code if you can. That should clear it up if it is bad gas.

dc5itr888

I deleted the code with my Actron OBD II reader and drove about 8 miles with nothing yet...question If I clear the code and nothing comes up again am I in the clear? Or is clearing it and doing nothing ( I havent purchased any gas today but I was told by the computer im on reserver gas) hiding the issue with my car

Mort

If there is still an issue the code will come back. The code will likely still be held in history if you wish to review past codes unless you clear the history as well. If the car is not showing any obvious signs of malfunction you should be fine to clear a code and see if it returns or if it was just a momentary issue.

roadtalontsi

its not bad gas. probably a vacuum leak at intake manifold gasket. bad gas causes misfires and rough starts not fuel mixture codes.

exdes

another vote for intake manifold gasket..

dc5itr888

i think you guys are right...The code came back today and its the same exact one.

P0171

I read somewhere that it could possibly be a purge valve as well. Going to call my third party warranty ( AAGI) and see how they work

Does anyone have them as well? I dont recall the details of my 3rd party warranty but I believe if its a 3K fix job my deductible is 100 $. But what if this is a small problem is it free?

I just tried calling and they are closed so will probably call tomorrow to find out more info about it

Dogtag114

+1

Happened to me twice. First time they replaced it, second time they sealed it.

HoozyerdaddyC63

I had the same issue and code. Turned out to be the intake manifold gasket.

I am still under factory warranty so I don't know what the cost would have been.

dc5itr888

I hope thats it... I believe CoolBeans has the same exact issue with the P0171 code and after reading his thread I hope I dont have to endure that.

On a 2nd note, I just contacted my third party warranty ( AAGI) and they said my warranty was voided?

After back and fourth calls with them and the dealership I got my car (Non MB)

Im bringing my car back to dealership I got it from and having one of their "journey" techs take a look at it while they resubmittted my contract for the extended warranty after a few months I have purchased it.

I dont know how I feel about dropping it off at non MB dealership and having them work on it.

Supposely they work on BMW, Audi and MB besides working on Toyota, Cadillac, and vary of American cars

dc5itr888

UPDATE:

I finally took my car in and it took them a week and they changed out the Intake Manifold Gaskets as someone mentioned.

Only time will tell if this resolves it.

abcut973

Still no CEL?
Was your car reving high in idle?

sinape62

I had a P0171 on my wife's C230k...turned out to be a vacuum leak. My code reader can run active graph and ran it to look at the MAF... like the previous post, at idle the car would run ~45 bar (when normal) and when it would idle higher the MAP would drop to ~35 bar. Mine happened to be a vacuum leak associated to an o-ring missing at the master cyl to brake booster... the master cyl was changed by an independent shop the day before, so I was focusing on the work they proformed. Mind you I was getting a CEL too, but the independent shop said the work they did to replace the master cyl was not associated to the CEL... but there were a definite "hissing" sound.

In anycase, any vacuum leak can affect the CEL, so this is not to say this is your problem. I happen to take the car to MB dealer and confirmed my suspicion. They took photos of the missing o-ring.