05 5.3L Tahoe Misfire/Running Rough Issue; Stumped

[Kaeden]

Thanks for all the input guys.

I replaced the MAF under warranty on my lunch break today. Immediately after replacing the MAF it still didn’t want to stay running, however after about 5 minutes of messing with it, it started running somewhat normal again. Something still isn’t quite right because it starts rough and seems to idle a bit odd. Looking at my scan tool and the live data, I’ve discovered the following:

FUELSYS2: CL_FAULT (Why is there a fault?)

P0061: HO2S Heater Resistance Bank 2 Sensor 3 (Where even is a sensor 3? I was only aware of 2)

This problem is getting really frustrating as nothing I’m doing seems to help. Any new feedback?

Thanks again!

 

[swathdiver]

Thanks for all the input guys.

I replaced the MAF under warranty on my lunch break today. Immediately after replacing the MAF it still didn’t want to stay running, however after about 5 minutes of messing with it, it started running somewhat normal again. Something still isn’t quite right because it starts rough and seems to idle a bit odd. Looking at my scan tool and the live data, I’ve discovered the following:

FUELSYS2: CL_FAULT (Why is there a fault?)

P0061: HO2S Heater Resistance Bank 2 Sensor 3 (Where even is a sensor 3? I was only aware of 2)

This problem is getting really frustrating as nothing I’m doing seems to help. Any new feedback?

Thanks again!

I don't even have those codes. Crawl under at your first opportunity and check the wiring of all four O2 sensors. What kind of reader are you using?

As for the MAF, give it some time to relearn but this other problem may prevent that. An advanced scan tool would be nice to have right now.

 

[Kaeden]

I’m just using a generic scan tool I got on amazon forever ago. Would a Bosch CodeConnect be any better?

 

[swathdiver]

I’m just using a generic scan tool I got on amazon forever ago. Would a Bosch CodeConnect be any better?

I don't know, try it. Tech2 would be best.

 

[Kaeden]

I don't know, try it. Tech2 would be best.

Gotcha, I’d love to have one but it’s a bit out of the budget at the moment. I’m gonna try looking at some of the wiring for O2 sensors and such, and well as try the Bosch code reader when I get off tonight and I’ll let you guys know what I find.

 

[swathdiver]

Gotcha, I’d love to have one but it’s a bit out of the budget at the moment. I’m gonna try looking at some of the wiring for O2 sensors and such, and well as try the Bosch code reader when I get off tonight and I’ll let you guys know what I find.

Post up where you live and maybe someone who has one lives nearby. More and more fellas on here are buying them as they generally pay for themselves in short order.

 

[Kaeden]

So I’ve determined that I’m pretty sure the 5V reference wire has a short somewhere. Just not sure where, but it’s throwing an 02 Sensor B2S2 code and the sensor reference code so I checked the sensor wire and it’s voltage was little to none. Now to find the short. Any suggestions? I’ve looked at all the obvious places and don’t see anything.

 

[swathdiver]

So I’ve determined that I’m pretty sure the 5V reference wire has a short somewhere. Just not sure where, but it’s throwing an 02 Sensor B2S2 code and the sensor reference code so I checked the sensor wire and it’s voltage was little to none. Now to find the short. Any suggestions? I’ve looked at all the obvious places and don’t see anything.

Gotta follow it all the way back to where it goes into the cab. Look for chafing and pinching and check the connector thrice.

 

[Scottydoggs]

did you clear the codes after installing the new maf?

rear o2 should not cause the running issues.

 

[Kaeden]

did you clear the codes after installing the new maf?

rear o2 should not cause the running issues.

Yes. The MAF Sensor code has stopped coming up since replacing the MAF. However I still have the O2 B2S1 code showing up as well as the Sensor Reference code. I tested the wire resistance from what I believe is the Sensor Reference wire on the O2 Sensor to the Reference Wire on the PCM connector, and the resistance leads me to believe there is a short somewhere. And yes, I realize that the rear O2 should not affect performance however if it is on the same Sensor Reference circuit as another sensor, another sensor could be having issues as well without necessarily throwing a code, such as the front O2 sensor.