02 Sensor issuse Solved

[altima03beast]

Sept 2 was my bday so when i got paid sept 3 i chose to fix all these dam codes p1166 , p0158 p0159 p0138 and p0037. got headers OBX . now nissan didnt want to touch my car so i took it to T&R racing in queens they did a great job . He told me i need a cat so i said lets go with a highflow cat and he changed all sensors . she runing great now and pulling faster . let me know what you think

[SlateSER1788]

I want to order some OBX headers before the weekend and I noticed (just like a lot of header setups) there's a few 02 sensor ports. On my Spec-V I made a "bung" to offset the 02 sensor on one of the 02 sensor ports and I never threw a code. Is this what the guys at T&R Racing did for you?

[Darius]

No, he's saying they inserted a high flow cat downstream of the OBX header and then put the second O2 sensor behind it. So, it is effectively setup like stock with the cat in there.

I have a Stillen header with no cat and the CEL is always on because the O2 sensors are reading too close together. The Stillen module does not work and they won't give me any customer support since I didn't buy it directly from them. p******. (Yes, still bitter) If I was worried about the environment or the CEL, I'd have a high flow cat inserted and put the second O2 sensor behind it. But the car runs fine and still gets the same crappy mileage (25 mpg highway).

[altima03beast]

No, he's saying they inserted a high flow cat downstream of the OBX header and then put the second O2 sensor behind it. So, it is effectively setup like stock with the cat in there.

I have a Stillen header with no cat and the CEL is always on because the O2 sensors are reading too close together. The Stillen module does not work and they won't give me any customer support since I didn't buy it directly from them. p******. (Yes, still bitter) If I was worried about the environment or the CEL, I'd have a high flow cat inserted and put the second O2 sensor behind it. But the car runs fine and still gets the same crappy mileage (25 mpg highway).

hey guys actually i havent been lucky . tnr put a 02 extender which cleared p0420& p0430 . after i sent that post to yall before i thought they fixed the problem to all those codes then i started getting the p0420 & p0430 back. after they got the 02 extender they cleared the p0420 and p0430 now m getting back p0138 and p0158 . he said that it might have to do with the bad mass-airflow sensor i got. now my question is this if after we install the new MAF and clear the codes and they come back the guy at the shop said that he will move one of the sensors further to the rear do you think this will help . Or should i just get a sensor for the front of the highflow cat and the back . the funny thing is that he keeps telling me that my car didnt come with a sensor in the front and the back of the catt.

[Darius]

He obviously doesn't know what he's talking about. Sounds like a reputable shop Take it somewhere else. Period.

The MAF error codes are P0101, P0102, P0103. The MAF is not bad or you'd know it immediately because you wouldn't be able to rev the engine above ~3000-3500 rpm.

All of the codes you have listed in your initial post are from the O2 sensors thinking the cat is not fuctioning properly because they are reading too similarly (i.e. same exhaust temperature). Make sure the first O2 sensor (wideband) is upstream of the cat and the regular O2 sensor is downstream of it. Does the car act any different with the Malfunction Indicator Light (MIL) on? I'm guessing no, so you have two options:

1) Live with the MIL staying on.2) Go back to stock. (probably not an option though)

I have been thinking about this for about a year since my gf's car has the same issue. She has the Stillen header with cat delete and the rear O2 sensor has two spacers on it and it still throws a MIL. I'm considering taking one of the spacers completely out and then drilling a small hole in the side of the remaining one to allow cooler fresh air to hit the rear O2 sensor. This will make it think it is downstream of a functioning cat since the EGTs will be lower. The only trick is to figure out how big the hole should be. I would start off as small as possible and work up until it doesn't throw a code anymore.

Can someone else chime in on that possible solution? I have been thinking about that forever and just haven't had time to try it.

[SlateSER1788]

Well I know the "O2 spacer" helped on my Spec-V but the trick with that was I used a different O2 sensor around the same time that I used the spacer. When I took my old one out (approx 80k miles) the O2 sensor was visibly bad.

Maybe try a new O2 sensor with the combination of the spacer? I know I had to put my spacer on my header, not on my mid-pipe.

[altima03beast]

car is fixed the moved the 2 02 sensors to the back where the cat is car is running well im so happy now we were all right and i kept telling him until he read about it on maxima.orgdarius my car use to go into Limp mode . gone now im so happy thanks guys