Code 23 - New MAF not helping

[theclerk95]

Hi I have a 2001 Legacy B4 rev c auto. I am running a fmic, apexi intake, zerosports hardpipe, full decat, dw65c fuel pump, gfb recirc, and am dyno tuned.

 

 

Am having some issues diagnosing my issues after receiving a code 23 for the MAF.

 

 

I took the car to the dragstrip at the beginning of August and the first run out the car bogged down really bad and it boosted but felt like it wasn't getting any power. The car did switch over to secondary as well and at the right rpm's. It didn't throw any CEL's but after looking everything over and tightening my piping clamps, the second run was no better and the issue was still there with no CEL. Decided to plug in my connectors and the car had a code 23 for the MAF sensor.

 

 

Forward to last week and my local dealer finally got an oem MAF in for me, I installed it and the car didn't feel much better and after less than 100km the issues were back and the code 23 was back (again no CEL).

 

 

Had the dealer test the MAF to make sure it was getting enough voltage and was reading correctly, and they confirmed it was, and the looked at my o2 sensor voltage as I noticed after logging it it was a bit off.

 

 

The o2 sensor at idle was jumping all over from 20mv up to 800mv down to 0mv and up 700mv... well you get the point. They confirmed the same, so I am going to replace the o2 Tuesday as I have a new universal Bosch at home.

 

 

 

 

 

Just wondering if anyone else may have some insight on this issue, because if this o2 isn't the issue then I am not sure what to look for next. I had issues with the o2 before and it through a code 23 for that but it also had the code 32 which is for the o2 sensor when it did.

 

 

Any help is appreciated thanks!

[ehsnils]

Have you checked for vacuum leaks including state of the PCV?

 

 

Others have also reported issues when the exhaust system has a leak before the O2 sensor.

 

 

A bad injector delivering fuel unreliably can of course also be a factor.

[theclerk95]

Have you checked for vacuum leaks including state of the PCV?

 

 

Others have also reported issues when the exhaust system has a leak before the O2 sensor.

 

 

A bad injector delivering fuel unreliably can of course also be a factor.

 

So I actually decided to get the car smoke tested after I installed the o2 and the problem persisted.

 

Almost immediately the catch can started leaking out of every seal. Seems the orings had rotted and the gaskets weren't doing their jobs either. Figure it must be the issue as it was leaking like crazy with just the pressure of the smoke machine, so I would imagine the amount of air that was leaking in or out would be a lot when the car was running.

 

Had a new catch can at home anyways so replaced it today and am hoping in a few days of driving the code and problems stay away