Question about 2004 Hyundai Santa Fe

1 Answer

2004 Hyundai Santa Fe. Bank 1 Sensor 1 O2 sensor stuck at 360 mv. Fuel trim at 10%. No codes. Fuel milage has dropped. Replaced O2 sensor with dealer part. O2 sensor still not moving. Also, maybe not related, clock resets contantly and radio and PRNDL lif\ghts seem dimmer.

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Master
  • 1,280 Answers

Replace the 02 upstream sensor... best solution

Posted on Apr 08, 2011

  • 5 more comments 
  • Brian Simpson Apr 08, 2011

    Already replaced bank 1 sensor 1...still stuck at 360 mv.

    PAUL MC G Apr 09, 2011

    Ok... this is gonna take some time. The 04 Santa Fe came with 3 (three) different/possible engines -- the 4 Cylinder 2.4 lit, the 2.7 V6, and the 3.5 V6. Only the 2.4 (4 cyl) and the 3.5 V6 are equipped with EGR. The 2.7 does NOT have EGR. Malfunctioning jEGR systems have been known to affect fuel trims (as you mentioned 10% (but you didn't mention if the 10% was a 'LEAN' condition or a 'RICH' condition. You describe a condition which can be caused by several different systems. First of all, it could be a clogged/restricted catalytic converter. Also, there could be an air leak (vacuum or exhaust), another is wiring/connectors/connections, and finally, the ECU/PCM (Engine Control Unit/Powertrain Control Module). Each of the systems would require IN-DEPTH discussion/explanation and illustration -- which is hardly worthwhile here on FixYa.

    The issue concerning the digital clock resetting or the PRNDL lights being dimmer is a 'separate' electrical system to the EMS (Engine Management System) wire harness... two separate wiring harnesses.

    Since I cannot see/touch the vehicle physically, the best (short-term) advice I can offer you is to have the problem/issue properly diagnosed by a competently trained Hyundai technician.

  • Brian Simpson Apr 16, 2011

    The problem stared with the Hyundai dealership. It started loosing gas mileage after the last service and has never been the same. I am an ASE Master Certified tech and am capable of handling the problem, but I have exhausted every resource I can think of to fix the problem and thought there might be a common odd problem for this. It is the 3.5 L engine and yes it is 10% lean. I did find the EGR valve leaking with a smoke test and it has been replaced, but oddly didn't change the trim. Cannot find any vacuum or exhaust leaks. I was finally able to get the Modis to communicate and found that it must have been the other scanner that was only reading 360 mv for bank 1 sensor 1. It does move as it should, but the lean condition is still there. Timing marks are dead on. I did notice that the rear O2s move around a little more than normal which is leaning me towards the cats, but I don't want to drop that kind of dough into it if this isn't going to fix it. I have a feeling that the dealership burned the cats up because they are doing fuel injection cleanings on this car every 15,000 miles and the last time she picked the vehicle up, it ran terrible. She took it straight back and they had the car for a bit and said it was fine and it magically ran fine which makes me think they either left the vacuum line they used off or the over loaded it with cleaner and burned up the cats. This is just a frustrating diag.

    PAUL MC G Apr 21, 2011

    You mention you're an ASE Master Certified tech ??? Then you know (as well as I) that the 'lean' condition can be:
    1. intake leak (whichever bank)
    2. defective 02 snsr
    3. clogged injector(s)
    4. restrictive CAT(s)
    5. Wiring/connectors/connections
    6. Defective MAF - You didn't mention whether the "lean" condition was isolated to just one bank or both

  • Brian Simpson Apr 21, 2011

    What's with the ???. It is bank one that is 10% lean. I have checked the intake for leaks by adding alternative fuel. Changed bank 1 sensor 1 because I thought it was stuck but had the same readings with new dealer part. Come to find out it was the scanner that was stuck, not the sensor. Can't be the MAF because it is only one bank, but have cleaned it anyways. Thought about injectors, but haven't had any poor running issues and killing the injectors makes a very noticeable change to the idle. That is why I posted the question on here, to see if there was a "competently trained Hyundai technician" that had any insight on any strange common problems for this condition. And you forgot fuel pump and other vacuum leaks on your list of possibilities for a lean condition, by the way.

    PAUL MC G Apr 22, 2011

    Ok then... fine! The Hyundai 3.5 lit V6 requires the same environment as any other make/model vehicle. If you trust that the O2 snsr is operating properly, then you can trust it. My research into your issue turned up nothing of consequence.... standard diagnostic procedures apply here.
    There's obviously more air than fuel getting to one (or more) cylnders on BANK 1. A lean code can be set even if only ONE cylinder is "LEAN." I'd speculate this 'LEAN' condition could be a result of 'garbage' in memory of the PCM (Powertrain Control Module). Suggestion: Try ZEROing out the computer (ECU/PCM/ECM) by disconnecting the negative battery cable and connecting a jumper wire between the positive (+) and negative (-) CABLES for 1 minute. This will WIPE any data in the computer's memory and it will have to 'RELOAD' the program/software from the EPROM. This SOMETIMES clears up issues which can't be resolved otherwise... it's a shot (in the dark).

  • Brian Simpson Apr 23, 2011

    I already tried reseting the adaptives that way with no change. Looks like I will just have to dig deeper.



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Where is the 02 Oxygen Sensor before the cadalic converter on a 2006 Hyundai Santa Fe

Usually these are located on the exhaust manifold or just below the exhaust manifold and you should be able to see it in the engine bay. On V6 engines there will be one sensor on each of the 2 exhaust banks.
You will probably need to remove the engine cover to see the sensors on your exhaust.

If someone told you to replace these because you got a particular fault code I would be wary. A decent scan tool and basic diagnostics can show if the 02 sensor is working or not. Some faults often blamed on an 02 sensor are not due to faulty sensors.

Jan 09, 2016 | 2006 Hyundai Santa Fe

1 Answer


Code 174 means the fuel mixture for bank two is too lean.
Bank two is usually the side with cylinder number two.
The problem could be the O2 sensor or one of the fuel injectors.

Sep 11, 2014 | 2002 Hyundai Santa Fe

2 Answers

2001 hyundai santa fe with obd 2 code po172 i bought this vehicle and now it wont pass smog

An O2 sensor is never the cause of a fault code P0172, you through your hard earned money away. Read about the code and the possible causes at the link below.

P0172 OBD II Trouble Code System Too Rich Bank 1 YourMechanic Advice

Jul 09, 2017 | 2001 Hyundai Santa Fe

1 Answer

Error code p0183 where is this sesor and what doest hurt

the o2 sensor [bank 1 sensor 2] is located after ur catalytic converter jack up and support truck follow the exhaust pipe u will see after the converter mounted in exhaust tube towards top a wire and sensor thats ur o2 sensor disconnect wire and unscrew sensor and replace -also check wiring and connection for damage ---it is an emission sensor will usually cause vehicle to fail an inspection can cause problems with fuel consumption[run rich]

Aug 23, 2011 | 2004 Hyundai Santa Fe

2 Answers

How many oxgen sensors does a 2004 Hyundai Santa Fe 2.7 2wheel drive vehicle have and where are they located? What idoes Bank 2 Sensor 1, Bank 1 Sensor 2, Bank 1 Sensor 1, and Bank 2 Sensor 2 mean?

you have 4 O2 sensors, bank one is the front cylinders ( close to the readiator ) there is 2 bank 1 O2 sensors one infront of the catalitic convertor ( bank 1 sensor 1 ) and one after the convertor ( bank 1 sensor 2 ) the same on the back cylinders they are bank two sensors 1 & 2 i will try to post the location of the wiring plugins if you find the plugs then you can folow the wiring to the sensor....good luck





Jul 01, 2011 | 2004 Hyundai Santa Fe

1 Answer

What can cause a 2005 Hyundai Sante Fe check engine light to come on and get all these codes: p0134 - o2 sensor circuit no activity detected (bank 1 sensor 1), p0151 -oxygen sensor circuit,low voltage...

i would check ur fuses that supply voltage to ur o2 sensors, their in the fuse box and usually r labeled o2 sensr. sounds like the o2 sensrs dont have power

Apr 09, 2011 | Hyundai Santa Fe Cars & Trucks

1 Answer

Error code P0421 how to fix it. which o2 sensor gets replaced?

P0421: Warm Up Catalyst Efficiency Below Threshold (Bank 1).

This could apear because of a bad O2 sensor on the catalytic converter on bank 1.

Or The catalytic converter is no longer functioning properly.

Hope this helps you. Good luck bro

Jan 09, 2011 | 2002 Hyundai Santa Fe

1 Answer

I am getting a engine code that says p0130 o2 sensor bank 1 sensor 1,my question is,where is the bank 1 sensor 1 location?

If your vehicle has a V-6 then it would be the first o2 sensor on the exhaust coming of the front of the engine.If it is a 4-cylinder. then it will be the first o2 sensor coming of of the engine.

Oct 02, 2010 | 2004 Hyundai Santa Fe

1 Answer

2006 hundai elantra P2270 code. If this is an O2 sensor, which one?

Possible O2 sensors:

P2270 O2 Sensor Signal Stuck Lean Bank 1 Sensor 2
P2271 O2 Sensor Signal Stuck Rich Bank 1 Sensor 2
P2272 O2 Sensor Signal Stuck Lean Bank 2 Sensor 2
P2273 O2 Sensor Signal Stuck Rich Bank 2 Sensor 2
P2274 O2 Sensor Signal Stuck Lean Bank 1 Sensor 3
P2275 O2 Sensor Signal Stuck Rich Bank 1 Sensor 3
P2276 O2 Sensor Signal Stuck Lean Bank 2 Sensor 3
P2277 O2 Sensor Signal Stuck Rich Bank 2 Sensor 3
P2278 O2 Sensor Signals Swapped Bank 1 Sensor 3 / Bank 2 Sensor 3
This is Bank 1 (closer to the dash panel) Sensor 2 (located after the catalytic converter).

Note: A malfunctioning front oxygen sensor may cause fuel trim codes to set.
  1. Several Diagnostic Trouble Codes use specific terminology to refer to sensor location. The illustration and key below explain the following terms:
  2. Engine BANK Bank 1 is closer to the dash panel, (also referred to as RH or right hand). Bank 2 is closer to the radiator, (also referred to as LH or left hand).
  3. UP Refers to Sensor 1 or "front sensor". It is located closer to the exhaust manifold and before the catalytic converter.
  4. DOWN Refers to Sensor 2 or "rear sensor." It is located after the catalytic converter.
  5. The following examples show how to interpret oxygen sensor terminology:
  6. B1/S1 = Bank 1/Sensor 1 = Dash panel side, BEFORE the catalyst or "upstream"
  7. B2/S2 = Bank 2/Sensor 2 = Radiator side, AFTER the catalyst or "downstream"

Aug 06, 2010 | Hyundai Elantra Cars & Trucks

Not finding what you are looking for?
2004 Hyundai Santa Fe Logo

1,265 people viewed this question

Ask a Question

Usually answered in minutes!

Top Hyundai Experts


Level 3 Expert

76848 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8582 Answers

Are you a Hyundai Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides