Hello everyone,

I recently picked up a 2001 XG300L. It's my first Hyundai and I love it. Unfortunately I ran into my first problem.

The check engine light came on. I checked the codes and they came up as: P0171 and P0174, which I understand is lean exhaust codes on oxygen sensors, bank 1 and bank 2. I replaced the fuel filter, but that didn't take care of the problem. I also cleaned the Mass Air Flow Sensor. I also checked for vacum leaks but found nothing. (The car is running fine)

Here's the question: What's next?

Should I go ahead and start replacing the oxygen sensors or try something else?

Thanks in advance.

Brad

EDIT: It has about 87,000 miles.

UPDATE: Replacing the Mass Air Flow seems to have fixed the problem. No check engine light and no stalling in about 2.5 weeks. Thanks to -byronguidry3732- for the solution. :clap:

This post has been edited by bradrel: Sep 28 2007, 08:08 PM

welcome to the forums :00000732:

you say that the car is running perfectly fine. if thats the case l would disconnect the battery ground lead for a few mins. to turn the light off and re-set the computer, run the car again and see what happens, if the light comes on again with the same fault code it looks like you may have to change the sensors

Thanks for the reply!

Unfortuantely I have reset the codes several times, each time they have came back on within about 20 miles.

Brad

This post has been edited by bradrel: Jun 9 2007, 07:41 AM

I have the same problem and its probably the MAF sensor. I cleaned the heck out of it one time, reset the codes, and the check engine light didnt come on for about 120 miles and when it did i didnt notice any difference. I just clean it periodically and dont have any issues including fuel economy. It's just one of those things Hyundai didn't resolve. but hey, if u come across any developements let me know. i wouldnt worry about it unless u come across noticable problems.

Hi.

Do You want to check Your exhaust fumes in shop with such equipment ?
It can show wether the cars fuel mixture is correct or not. If its not , You may be losing in cars preformance and also braking the law.

Take care,
Mihkel

Crazy, I am experiencing the same thing now. But my car will shutter at start up sometimes, or randomly. I need to take it in...

Dear bradel,

:00000732: first.

Did you know that you have a specific Tech Service Bulletin for P0171 and P0174 on your car?

[Pause for slow bow to roaring applause]

Byron :whistling:

Attached File(s)
 XG300_Code_P0171__P0174_04_36_020.pdf ( 21.56k ) Number of downloads: 188

:clap: (Roaring Applause) :clap:

Thanks!

I will be checking this in the next week or two.

Brad

So, I wonder why it is that the service department managers and technicians acted like I was crazy when I brought my XG in due to those codes. They tried to tell me that the folks at Autozone and Advance Auto had "cheap scanners" and that it was the output speed sensor that had to be replaced. Once that was replaced and the codes were still there, they said I needed to replace O2 sensors which I had just had replaced. I'm going to take this bulletin in and let them read it and see what they have to say, then I'm going to tell them that I'm taking my car to another Hyundai dealership and report it to the Hyundai consumer affairs people.

Dear angieb,

NEVER assume that the service tech is smarter on your car than you are. NEVER.

Real life: I actually had to print out the alignment specs for my Santa Fe when they set it wrong and fold their little tiny fingers around the piece of paper for them to get it right.

Also, I caught them using an impact tool on the rear camber adjustment nut. So I printed off the TSB warning not to use impact tools on camber adjustment nuts or damage will result...etc.

Always be prepared to hand them the TSB. Shame on them but such is the service departments at most dealers these days.

Also, don't assume the salesperson knows more about the car he/she is trying to sell you than you do. They don't.

Byron

Called Hyundai Consumer Affairs about the Tech Svcs Bulletin and e-mailed them a copy of it in addition to my "dispute" with the dealership. They refuse to admit the MAF is a problem and have said it needs a tune-up, throttle position sensor--when I know the MAF is bad and the catalytic convertor is as red as a cherry and smelling like rotten eggs. I still have warranty left on the convertor and the MAF because of the extended protection warranty I got as a result of the class A suit on the horsepower that was misrepresentated on the XG's and other models. Having a "battle royale" and may have to get my congressman in on the act. There's definitely power in numbers, and if there's a TSB on the MAF, maybe they'll do a recall if enough folks complain.

I have the same problem, the lean codes on the left and right banks. I changed a fuel regulating valve, but that only worked for a week. The codes go out periodically, but the always come back. My car shutters sometimes also, so I took it in to get the codes read and they said I had a misfire in cylinder #6. So, I'm going to change the spark plug in that cylinder. The problem is that I don't know what cylinder is #6.

I don't think both of my O2 sensors failed at the same time, so I don't think that is the problem. I guess I'll look into the MAF next.

I have the exact same problem. I got the check engine light last year, and it said that I had lean fuel on left and right bank O2 sensors. I didn't think both of my sensors failed at the same time, so I thought the engine wasn't getting enough fuel. I took off the engine cover and physically agitated (hammered) the fuel reg valve. This helped for a little while, but the light came back. The light was intermittant for the next year. Then, my car started to shutter sometimes. So, I got the code read again,and they said I had a misfire in cylinder #6. I didn't know which cylinder 6 was, but I knew it was in the front of the car, so I changed the plugs in 2,4,6 to be safe. I would have changed 1,3,5 but they are under some type of manifold/cowling. My car runs better now, but I still have the check engine light. After reading this forum, I bought a MAF online on ebay. It was about $80 cheaper than the dealer. I'm going to change it tomorrow and I'll let you know what happens.

hey all old topic i know but just got these codes after changing my egr solenoid i was wondering if any 1 finally picked out the problem ive spent so much money on the car already and its 1 head ache after another if i cant figure out the problem im going to just sell the car i got lean bank 1 and 2 please help

ANY 1?