P0130 CEL

[ryankenn]

I know, its been covered, and I've read the threads portaining to it. I myself posted a problem about a CEL I had, with good responses. Not having a OBD-II scanner at the time, I figured the advice was correct.

I have a 2.5" Borla header back exhaust. Right where the first turn is ater the header is the first O2 sensor, then about 14" later is the Magnaflow cat, then the second O2 sensor. I had to extend the wiring of that second sensor about 2.5 feet to reach its new home. I also have installed the plug fouler fix on that rear sensor. Both sensors are new with the exhaust, front from Subaru, rear Bosch I got online.

I thought I was getting a P0420 for too much flow, hence I tried the fouler fix. I also had ordered an I-speed reflash, and had it not work out, as under 2000rpm the car would misfire and sputter once warm. The whole time I've had a CEL. I bought the bullitt and purchased an OBD scanner.

The code returned was P0130, which is the front sensor. Now, having changed it very recently, I'm hoping there is some advice on how to test the sensor to see if its bad. The scanner I have can take a FREEZE of all the sensor data when the CEL was recorded, but not a live feed, so I can't see what kind of readings that O2 sensor is giving while its running.

ALso, that CEL is for a "lean" condition, which explains why my car is such a huge gas pig, as its trying to desperatly compensate for what it thinks is lean running.

Does anyone have any data that I can measure the cold resistance of the sensor to get an idea of whether its already gone bad? I'm going to try to find the original sensor I replaced and put it in to see what happens, as I didn't swap them because I was getting CEL's, I did it just because the whole exhaust was coming out anyways.

Thanks,
Ryan

[ivwarrior]

Given that the sensor is new, I think the first thing I'd do for a lean exhaust code would be to check all your engine vacuum hoses and make sure all are connected and none are cracked/split etc.

[ryankenn]

Is there any secret method to expidiate the process of finding a vaccuum leak, ie listening device or smoke or something, or is it a process I'll just have to go over all of the hoses to look for signs of wear/leakage.

I did find the original sensor today as well ( finally something I kept I need! ) so I'm going to throw it in tonight and see if it makes any difference.

Ryan

[ryankenn]

Found a vaccuum hose backed of its nipple about 2/3rds, and also changed out the air/fuel ( front O2 ) to the old unit, and finally, success!!!

No more CEL thus far. It normally came up almost instantly, so after an hour of driving without it, I think either the vacuum hose, or sensor was faulty. Smells better out of the arse already.

One thing this did allow me to do, was try the I-Speed flashed ECU again, and it brought up a CEL almost right away. It also did not allow the OBD-II reader to connect to tell me what it thought the CEL was, so there is definitly somthing between a RS ECu and Legacy ECU that don't work together.