Hyundai Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
2002 Sante Fe, 2.7 300+Km,
I am stumped, I had P0171 & P0174 codes show up indicating the oxygen sensors detected a lean condition in Bank 1 and Bank 2. The car was using an excessive amount of fuel so since I have never changed the O2 Sensors I figured it was a bad sensor.
Changed out Bank 1 upper sensor, cleared the codes and they both returned after about 100km... Changed the Bank 2 Upper sensor and to eliminate it, thought why not change the fuel filter at the same time... After the filter was changed, the Sante Fe was difficult to start and started backfiring through the intake and has no power. Checked all the connections, checked fuel flow (not Pressure) and still no joy. Checked the Mass Air Flow Sensor, it is clean. (Not sure what it is supposed to read on the meter.) Checked the Throttle Position sensor and it gives a couple funky jumps when going through the range but there was absolutely nothing wrong with the power or acceleration before this...

Went from a car that ran well but used fuel to a large ornament... Car Starts, Idles, but can't accelerate, and has NO Power, nothing. I am looking for suggestions or ideas...
 

·
senior member
Joined
·
22,793 Posts
You didn't accidentally dislodge a vacuum line, or have an electrical harness get disconnected? Bare wire exposed in the area? And these O2 sensors were the ones spec'd out for the car, yes? Matched the ones you removed? Bad new sensor, right outta the box? Sometimes happens.

I'm not smart enough to suggest anything further; I'll leave that to the forum experts. But I'd start looking at the simplest thing it could be, first, before dumping money into "suspicious" items that may not be faulty.

I've had my turns at throwing money into a car only to find out the problem was a loose connection., or a broken vacuum line. Stuff like that!
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #3 ·
All good suggestions! But I removed the new ones, reversed everything and still everything is as ì said.. new or old doesnt seem to make a difference now?
 

·
Retired Staff
Joined
·
11,818 Posts
Causes
A code P0171 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak downstream of the MAF sensor Possible cracked vacuum or PCV line/connection Faulty or stuck open PCV valve Failed or faulty oxygen sensor (bank 1, sensor 1) Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty fuel filter!) Exhaust leak between engine and first oxygen sensor

Possible Solutions
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include: Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace/repair as required Inspect all hoses and connections in the air intake system Inspect and/or test the intake manifold gaskets for leakage Check for a dirty fuel filter and proper fuel pressure Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool If you have access, you may want to run a smoke test

Info copied and pasted from http://www.obd-codes.com/p0171



Sent from AutoGuide.com App
 

·
Registered
Joined
·
5 Posts
Discussion Starter · #6 ·
Well, here is an update, as I said, the Throttle position sensor was giving weird readings.. that has been replaced. The car has since started and hasn't been able to idle well.. the latest culprit appears to be the Mass Airflow sensor but I can't find what the readings should be when metered... I did find what it should read if the car is running but no test that can be done off the car. (We're waiting for a replaccement MAF) We tore the covers off and verified the timing belt didn"t jump a tooth.... the vaccuum system and hoses are all intact. Checked for loose connections and bared wires, nadda... it idles, (roughly), so wierd...but still looking....
 
1 - 6 of 6 Posts
Top