hello, Im new here, sorry for new thread but
couldn't find what I needed with search function.

I have a cel code and cant get rid of. Codes are:
P0131
P0135
Both of these codes are on the 1st o2 sensor. One reads malfuntion and the other
meaning low voltage I believe. Now I just replaced the front o2 sensor and still same thing.

When I first bought this car I didn't know it but, the cel light was pulled out. Just put new bulb in
and now I cant get the problem fixed. What could be causing these codes and how can I get this fixed.
Maybe the sensor isn't gettiing gounded off good? some wire messed up somewhere?

Can the maf be causing this because when installing my aem cai I noticed someone stabbed through the honey comb looking part with like a screwdriver or something thinking it would get better air flow.
Dont know if this could have to do with a cel on the 1st o2 sensor but any information would be helpful.

I have a aem cai, ssa header and a magnaflow cat. 1st sensor on header and second one behind the cat.

 

Nice post.

First off, where is the first sensor at on the header? On ONE pipe, or where 2 pipes converge, or where all the pipes converge?

Second, have you checked the wiring?

THird, get your MAF replaced, he could have damaged something while stabbing at it, and the MAF needs that honeycomb there like it's supposed to be.

Fourth, have you reset your ECU?

 

1. It's on the fourth pipe.

2. No I have not checked my wires yet. Do they go all the way to the ecu?

3. I agree. where can I get another maf and whats the price range.

Yes. I have reset the ecu twice, but after about two start ups it comes back on while Im
driving or when its idling. Thanks for fast reply.

 

Ok, I checked the wires on the o2 sensor and they looked fine.
Has anyone here ever had these codes before. ANY opinions
or information on how to get this fixed will be appreciated.

MUST be able to pass inspection in less than two weeks.
Should I move the 1st o2 sensor on down to the midpipe??

PLEASE HELP ME WITH THIS GUYS!!!!!

 

We will. Be patient, the forums die on the weekends.

 

I'd say first things first. The MAF needs to go. That mesh is NEEDED to keep the airflow straight, without it, all sorts of problems will arise. Not 100% sure if it's causing the o2 sensor issues, but you'd better replace it anyway.
BTW, since tibs are usually hard to find in junkyard, you can use the same MAF from an Elantra with a beta engine. Should be pretty easy to get your hands on a MAF.

You have a header? What did you do with the 2nd o2 sensor? You had to extend the wires to reach, correct? Check your wiring.

And are you sure that the sensor is good? It could just be that the sensor has gone bad..

How did you go about resetting your ECU? Did you follow the DIY in the forums here? Because that's how you have to do it.

Also, this may be helpful

P0131 - Oxygen Sensor Circuit Low Voltage (1st sensor)
P0135 - Oxygen Sensor Heater Malfunction (1st sensor)


Webtech has a lot of information and testing procedures if you want to check there, just type in the year/engine and then go to search and type in the CEL code.



click here for Webtech

username is RDT, and password is Sm9vbw==

 

Yes, I have ssa headers. Second o2 sensor is fine, no codes.
I have replaced both sensors, first sensor on header and second sensor behind cat.
I thought that the sensor was bad too, so I replaced it again and still same codes.

Yes I reset the ecu correctly-twice......
still same codes

 

Fix the MAF yet?

 

First off replace the MAF sensor, if the maf sensor is getting a bad reading it may throw a MIL for the 02 sensor.

if you still have the CEL

Webtech says check the status of the piping downstream of the MAF sensor, look for leaks in couplers and or loose / missing vacuum hoses

Other than that or the harness being unplugged check the ground wire for the O2 sensor.

After that you need to purchase a multimeter and login to webtech @ hmaservice.com - Choose tiburon, year, 2.0L and then click shop. Then in the right hand side there is a search button, type in P0131. Enter. go through all troubleshooting procedures. Repeat for P0135.

Be sure you type zero-0 and not the letter O.

You will be checking various voltages and resistances under different circumstances, if you dont know anything about elictrical circuits and things of that nature you might want to get it looked at by someone.

Hope this helps.

 

I don't remember seeing it up there, but have you checked your exhaust manifold for cracks?