[Frontier17]

Hi, Guys, i did a stupid mistake, overfilled the engine oil recently, even i drained out some of , but the Engine Service Light is on, the error is P0171, my cab sometimes sells like engine oil... and sometime the engine is rattling, but not always, most time the performance is fine still, but i can feel the air in the cab is toxic, hard to breathe sometime, maybe the CO2 is too high.. so far i just changed the air filter, seems didnt help too much yet, and i am wondering the CAT converter is bad, but no funny sound from there, seems is ok, and most time, the horsepower seems as normal, anyone can give a clue pls, for a easy start... i need i should do a diag in dealer, :comphead:
thanks

 

[TheOregonFront]

code p0171 is a bad cat. as far as the other issues i dont have a clue man, you may have split oil on the block and as it gets hot it will smell bad.

 

[Frontier17]

thanks, i am thinking the same, but try to get around of it, hopefully, is expensive to change the cat

 

[TheOregonFront]

thanks, i am thinking the same, but try to get around of it, hopefully, is expensive to change the cat

oh no thats not what i meant, i meant the o2 sensor not the cat. your cats should be fine. as to the sensor, its cake you have the old one out and new one in in like a couple minutes. it seems the sesnors are anywhere from 50-100 bucks.

 

[joefrontier2]

How many miles on your rig? What year is it?

I'm going to bet you spilled it on something and it's burning off the engine.

 

[Frontier17]

oh no thats not what i meant, i meant the o2 sensor not the cat. your cats should be fine. as to the sensor, its cake you have the old one out and new one in in like a couple minutes. it seems the sesnors are anywhere from 50-100 bucks.

oh, i see, but i am thinking maybe more, as the engine sometimes is rough idling, the signal is right, i guess, there is something wrong, like they said, lean fuel, on bank 1....

How many miles on your rig? What year is it?

I'm going to bet you spilled it on something and it's burning off the engine.

not lots miles, only 70000 miles. is 2002, i will try to clean my engine, but, i am guessing the ordor is from intake somewhere, or maybe too much oil, and the pressurized oil into some area, i dont know where can be:comphead:

 

[TheOregonFront]

right, that is what it says when the o2 sensor is malfunctioning or deteriorating. bottom line, replace the o2 sensor. thats whats causing the CEL

 

[Q451990]

Check out Spark plug, Spark plug wire, spark plug gap, spark plug cross reference and ignition wires at Sparkplugs.com for the O2 sensors. I have been very happy with their "OEM equivalent" NGK and Denso sensors.

Heath

 

[Frontier17]

will check for sure, just need figure out, if the engine was over filled, wht could happen... right now seems combustion problem, either exhaust is blocked or the intake is blocked, my engine plugs seems fine, the plugs working well as well the wires, but the truck does have the bad ridling

 

[Q451990]

How much extra oil was in there?

Heath

 

[Frontier17]

1/2 liter

 

[Frontier17]

Thanks guys, will change my passanger side O2 sensor-upstream first, i think Bank 1 is p- side, to see if will solve the problem, could fix it, hopefully, bad is i am in CAnada, no cheap part you can get, so as the winter is cold here, :thatswck:

 

[devious1]

I would make sure your oil level is for sure correct and then run it up and down the highway multiple times hauling ***. Mine just recently has been throwing that code at 120,000 miles. A few thousand later of make sure everything is correct and then really getting on it to clear out the exhaust it shut the light off, near 10,000 later it has not came back on.

Cats are expensive and O2 sensors are not that cheap ether for a little sensor. Also, try washing the engine with some degreaser trying not to get too much water the the electrical parts. This may not completely clear up the problem, the rest of it will just have to burn off if not As far as the oil you should be fine as long as that extra oil was not in there for too long, you should already know if it was (truck would not turn over). Just have to deal with the smell for a little while.

 

[Frontier17]

So, what actually you 'v done? replaced the O2 sensor as well?

 

[BRUTAL]

P0171. P0174 Are Lean Engine Codes For Bank 1 And 2. Not O2 Sensors. And A Qt Overfull Of Engine Oil Wont Do Sh*t. You Have A Vacuum Leak Or Possibly A Faulty Mass Air Flow Sensor. With The Engine Idling, Spray Around Intake Manifold And All Vacuum Sources. Listen For Stumble. This Is The Shade Tree Method But Works, For Small Or Really Hard To Find I Monitor Short Term Fuel Trims With A Scanner. Barring Any Vac Leak Try Cleaning The Mafs With Mafs Cleaner From The Auto Parts Store. Also Replace The Psv Valve Since These Can Stick And Cause Lean Condition, So Can Leaving The Oil Fill Cap And Dipstick Loose. The Crankcase Is Under Vacuum As Well With The Pcv System. So Valve Covers Leaking Air And Other Seal Can Creat Problems Too. When You Think You Fixed It Clear Codes And Do A Hard Reset Of The Battery To Set Ecu Defaults And Clear Long Term Fuel Trims. If You Dont The Long Term Fuel Trim The Ecu Adapts To With Vacuum Leaks Will Not Self Correct Fast Enough Before You Get A Cel Again. Do This By Disconnecting Neg Or Postive Cable From The Battery(doesnt Matter And You Only Have To Do 1 But Both Are Ok) Touch 1 Cable To The Other For A Few Seconds. This Drains The Modules Capacitors(small Batteries To Retain Power To Modules Without Battery Power, This Is Why Air Bags Can Still Fire Without A Bettery Hooked Up) This Will Erase Long Term Fuel Trims

 

[Frontier17]

P0171. P0174 Are Lean Engine Codes For Bank 1 And 2. Not O2 Sensors. And A Qt Overfull Of Engine Oil Wont Do Sh*t. You Have A Vacuum Leak Or Possibly A Faulty Mass Air Flow Sensor. With The Engine Idling, Spray Around Intake Manifold And All Vacuum Sources. Listen For Stumble. This Is The Shade Tree Method But Works, For Small Or Really Hard To Find I Monitor Short Term Fuel Trims With A Scanner. Barring Any Vac Leak Try Cleaning The Mafs With Mafs Cleaner From The Auto Parts Store. Also Replace The Psv Valve Since These Can Stick And Cause Lean Condition, So Can Leaving The Oil Fill Cap And Dipstick Loose. The Crankcase Is Under Vacuum As Well With The Pcv System. So Valve Covers Leaking Air And Other Seal Can Creat Problems Too. When You Think You Fixed It Clear Codes And Do A Hard Reset Of The Battery To Set Ecu Defaults And Clear Long Term Fuel Trims. If You Dont The Long Term Fuel Trim The Ecu Adapts To With Vacuum Leaks Will Not Self Correct Fast Enough Before You Get A Cel Again. Do This By Disconnecting Neg Or Postive Cable From The Battery(doesnt Matter And You Only Have To Do 1 But Both Are Ok) Touch 1 Cable To The Other For A Few Seconds. This Drains The Modules Capacitors(small Batteries To Retain Power To Modules Without Battery Power, This Is Why Air Bags Can Still Fire Without A Bettery Hooked Up) This Will Erase Long Term Fuel Trims

Thanks a lot, actually i did smelled rotten egg once, before all the things happened, but is very good idea to check my Air Flow Sensor ... AFS is not cheap either

 

[Frontier17]

So i did take the flow sensor out, and check the resistance between the pins, seems there is no resistance at all bettween two pins, is that normal? or should have reading always, ..

just read the service guide for the truck, P0171 error, including all the possiblility fails from Massive control sensor, O2 sensor, also the pcv valve, for sure, i need dealer to do the diag, so can tell

 

[Frontier17]

A silly update, i found my intake hose clams was loose, tightened it up, problem solved, haha,,, thanks guys:itsfriday:

 

[justbecause]

A silly update, i found my intake hose clams was loose, tightened it up, problem solved, haha,,, thanks guys:itsfriday:

Wish mine was that easy, I'm trying to track mine down before I bend over to the tune of $120 at the dealer.

 

[D13FrontierLE]

Something to consider on 2nd gens. I just fixed this code (P0171) on mine, truck did not seemed to have any misfires, just the code coming back every 20-50 miles after erasing it. The heater core junction ("T") on the outlet side was slowing and finely leaking where no water was seen but if you would touch it, you could feel it wet around. It did have a very fine and small crack that slowly build droplets that later would fall over passenger side Oxygen sensor, thus throwing the code P0171, I guess the sudden change in temperature from coolant hitting the sensor and/or exhaust manifold would trigger a "lean mixture" reading. I ordered a brass T and got a hose and clamps from local auto parts store to fix it, did the heater core inlet piece as well with the Dorman aftermarket part and added coolant lost. About 135 miles after fix and code hasn't come back when last week it was becoming more frequent popping up after 8-15 miles after light reset.