o2 sensor problem or more?

[Kyle2k]

The first plan of action is just to make sure everything is tightened up to spec. If that doesn't work I will swap sides on the o2 sensors and see if I get the same sort of logs. I will report back later with the good/bad news!

[04GOAT-11SS]

The first 4 codes are all rear o2 sensor codes as you probably know. The P0154 is likely where your problem lies. The O2 sensor should be switching between 0-1v. A quick way to see if the 02 sensor is working is to wait for it to enter closed loop, create a small vacuum leak and make sure the voltage drops to around .1 volt momentarily. Then fix that leak, blip the throttle a few times and watch the o2 voltage. Should rise to nearly .9v. If they don't do that then it's time to start looking at the sensors, wiring etc. If it does that and it's just not switching enough (about 15 times during a 10 second time frame when holding the engine at 2k rpm) it's time to replace the sensor.

[thahemp]

Originally Posted by 04GOAT-11SS

The first 4 codes are all rear o2 sensor codes as you probably know. The P0154 is likely where your problem lies. The O2 sensor should be switching between 0-1v. A quick way to see if the 02 sensor is working is to wait for it to enter closed loop, create a small vacuum leak and make sure the voltage drops to around .1 volt momentarily. Then fix that leak, blip the throttle a few times and watch the o2 voltage. Should rise to nearly .9v. If they don't do that then it's time to start looking at the sensors, wiring etc. If it does that and it's just not switching enough (about 15 times during a 10 second time frame when holding the engine at 2k rpm) it's time to replace the sensor.

Good info thanks.

[Kyle2k]

Well, it has been awhile but the car runs and I've got some of my other responsibilities out of my way, but I still haven't fixed the issue - I attached a new(different) datalog if anyone would mind taking a look - the diablo data viewer link is right here. I also included the O2 sensor voltages in the log...something is odd here and I think it is bank 2 more so than bank 1 that is throwing everything off.

http://www.diablosport.com/forum/vie...hp?f=31&t=2335

[Badbubba]

If you can, swap the sensors and see if the issue switches to the other bank.

[thahemp]

Originally Posted by Kyle2k

Well, it has been awhile but the car runs and I've got some of my other responsibilities out of my way, but I still haven't fixed the issue - I attached a new(different) datalog if anyone would mind taking a look - the diablo data viewer link is right here. I also included the O2 sensor voltages in the log...something is odd here and I think it is bank 2 more so than bank 1 that is throwing everything off.

http://www.diablosport.com/forum/vie...hp?f=31&t=2335

I agree. Your bank 1 sensor voltage looks like it is supposed to. Bank 2 is jacked up. I don't know why though.

[thahemp]

Looks like you're getting a little KR when you tip into the throttle too.

[litle88]

You have two suggestions that I'd go look into when you get a chance. Do the header check and make sure there's no leaks or soot around the connections or off the cylinder head. Also make sure the o2 sensor is tight.

If that doesn't work, swap sensors out and then get back to us bud.

[thahemp]

Originally Posted by litle88

You have two suggestions that I'd go look into when you get a chance. Do the header check and make sure there's no leaks or soot around the connections or off the cylinder head. Also make sure the o2 sensor is tight.

If that doesn't work, swap sensors out and then get back to us bud.

Agreed. See if it chases the sensor.

[axis]

Originally Posted by Badbubba

If you can, swap the sensors and see if the issue switches to the other bank.

There's your huckleberry.

That would eliminate or find one problem source.

[Kyle2k]

Thanks for the advice guys, I have essentially done all the visual inspections for soot and I have found nothing around the heads - I will check to see if there is any around the sensors this weekend and if not I will just do the switch then.

For what it is worth it smells VERY rich on start up - occasionally bucks both after start up but then usually settles down with in 10-20 seconds and then also occasionally around town when I drive. However, when I get it back and turn it off it smells very lean. Other little tidbits - I am running one of the older two piece haltech intakes with the 102+mm MAF so bank 1 is reading high LTFT's because that's what I was told to expect (as opposed to some sort of exhaust leak) - the added headers probably isn't helping...

[axis]

Originally Posted by Kyle2k

Thanks for the advice guys, I have essentially done all the visual inspections for soot and I have found nothing around the heads - I will check to see if there is any around the sensors this weekend and if not I will just do the switch then.

For what it is worth it smells VERY rich on start up - occasionally bucks both after start up but then usually settles down with in 10-20 seconds and then also occasionally around town when I drive. However, when I get it back and turn it off it smells very lean. Other little tidbits - I am running one of the older two piece haltech intakes with the 102+mm MAF so bank 1 is reading high LTFT's because that's what I was told to expect (as opposed to some sort of exhaust leak) - the added headers probably isn't helping...

I'll trade you my yellowjacket for yours. I always wanted one of the older CF ones. Just couldn't pull the trigger for $600 though.

[Kyle2k]

Originally Posted by axis

I'll trade you my yellowjacket for yours. I always wanted one of the older CF ones. Just couldn't pull the trigger for $600 though.

I might consider it, I'll pm you once I get this thing running decently - I have the car up at the moment and I noticed soot marks at the exhaust clamp it is about 6 inches behind the o2 port? Do you think that could throw it off if it is behind the sensor? Either ways I tightened it and am contemplating switching sides on the o2 sensors anyways

[litle88]

Originally Posted by Kyle2k

I might consider it, I'll pm you once I get this thing running decently - I have the car up at the moment and I noticed soot marks at the exhaust clamp it is about 6 inches behind the o2 port? Do you think that could throw it off if it is behind the sensor? Either ways I tightened it and am contemplating switching sides on the o2 sensors anyways

Yes air can get sucked in and disrupting the o2's readings.