2007 Tahoe 5.3l AFM DOD delete thread

[wsteele]

The 02sensors closest to the headers so my upstream sensors are unplugged. Let me get the ypipe and upstream 02 sensors hooked up. I hope that's the issue what yall think?

The PCM relies on the upstream O2 sensors to adjust fuel trims in closed loop operation (upstream is in front of the cats). If there is no O2 sensor, then it hasn't got a way to know if that bank is running rich or lean. With the O2 sensors unplugged, I am surprised you only got a P0300 code.

Can you get your scan tool to look at the misfire counts by cylinder? (most will in Live Data mode)

 

[Taheezy_88]

The PCM relies on the upstream O2 sensors to adjust fuel trims in closed loop operation (upstream is in front of the cats). If there is no O2 sensor, then it hasn't got a way to know if that bank is running rich or lean. With the O2 sensors unplugged, I am surprised you only got a P0300 code.

Can you get your scan tool to look at the misfire counts by cylinder? (most will in Live Data mode)

I also got p0171 p0174 (if i remember correctly) lean codes. Ill search my scan tool. Thanks for the replies. I pray its just the o2 sensors being unplugged I gotta drive this Tahoe to Texas soon

 

[wsteele]

I also got p0171 p0174 (if i remember correctly) lean codes. Ill search my scan tool. Thanks for the replies. I pray its just the o2 sensors being unplugged I gotta drive this Tahoe to Texas soon

Good luck.

 

[Taheezy_88]

Good luck.

For the low oil pressure is it because that screen was removed?

 

[wsteele]

For the low oil pressure is it because that screen was removed?

I doubt removing the screen will cause a lower pressure reading, at least, I can't think of why.

It could be a number of possible causes, most of which I think have been mentioned. I believe there are a few different O-Rings that go on the end of the pickup tube. If you get the wrong one, it may cause the idle low pressure you are seeing. You could try the over fill on an incline method of checking that o-ring.

 

[Taheezy_88]

I doubt removing the screen will cause a lower pressure reading, at least, I can't think of why.

It could be a number of possible causes, most of which I think have been mentioned. I believe there are a few different O-Rings that go on the end of the pickup tube. If you get the wrong one, it may cause the idle low pressure you are seeing. You could try the over fill on an incline method of checking that o-ring.

Thanks Steele . The o ring I installed fitted pretty snug even before tightening I hope it's not the o ring cause I hate dropping that oil pan.

 

[wsteele]

Thanks Steele . The o ring I installed fitted pretty snug even before tightening I hope it's not the o ring cause I hate dropping that oil pan.

I understand, dropping the pan is a pain. I think you can eliminate the o-ring pretty easy by doing a test I first read about here from @iamdub. Maybe if we are lucky he will see this and chime in. Basically it is overfilling the oil by a couple of quarts and parking on a steep driveway nose down. If the idle oil pressure pops up, you know the o-ring is leaking air. If it doesn't change, you know it isn't an 0-ring problem.

 

[Geotrash]

Bummer on the oil pressure, man. I had low oil pressure after replacing the O-ring as part of my cam swap job, and ended up dropping the pan a second time and replacing the oil pump with a high volume unit and a new O-ring supplied with the pump. I could find no problem with the O-ring I removed when I installed the new pump, so who knows. They're finicky.

 

[Taheezy_88]

Yea it sucks trying to pin point it. I pray I dont have to drop that pan again. My oil filter was loose and leaking some oil a bit so i tightened it down more hope that was the cause will start up and run again. Oil pressure only drops at idle.

 

[Taheezy_88]

Update: y-pipe is on with upstream 02 sensor installed. All codes are gone thankfully.

I still have the "SERVICE STABILITRAK" warning sign on dash though. I have no clue why or how to clear it. Any thoughts?

Oil pressure surprisingly is above 40psi at idle after I drove around the neighborhood a bit. Hope it stays maybe needed to build up oil pressure idk.

 

[wsteele]

Update: y-pipe is on with upstream 02 sensor installed. All codes are gone thankfully.

I still have the "SERVICE STABILITRAK" warning sign on dash though. I have no clue why or how to clear it. Any thoughts?

Oil pressure surprisingly is above 40psi at idle after I drove around the neighborhood a bit. Hope it stays maybe needed to build up oil pressure idk.

View attachment 279846

There is a procedure to clear that message (if what caused it is rectified). I can't remember exactly, but entails turning the wheel 90 degrees one way then the other, then turning the ignition off for like 30 seconds. Google should get you to a place that will show the exact procedure.

 

[Taheezy_88]

I will look thanks Steele. Can a harmonic bolt back off after tightening. I noticed a slight wobble in my balancer.

 

[wsteele]

I will look thanks Steele. Can a harmonic bolt back off after tightening. I noticed a slight wobble in my balancer.

If you used the prescribed harmonic balancer installation procedure, it shouldn't back off. Did you do the torque the balancer on with the old bolt and then remove and install the new bolt and the torque to yield procedure?

Are you sure the wobble isn't just an optical illusion caused by the light and dark spots on the HB making it look like it is wobbling?

 

[iamdub]

I understand, dropping the pan is a pain. I think you can eliminate the o-ring pretty easy by doing a test I first read about here from @iamdub. Maybe if we are lucky he will see this and chime in. Basically it is overfilling the oil by a couple of quarts and parking on a steep driveway nose down. If the idle oil pressure pops up, you know the o-ring is leaking air. If it doesn't change, you know it isn't an 0-ring problem.

That's pretty much all there is to it.

 

[Taheezy_88]

Stabilitrak service warning light is gone. I unplugged the battery for about 10 minutes since I wasn't throwing anymore codes. Started back up and it's gone for now. Harmonic Balancer does have a slight wobble I will have to repeat the steps of install.

 

[wsteele]

Stabilitrak service warning light is gone. I unplugged the battery for about 10 minutes since I wasn't throwing anymore codes. Started back up and it's gone for now. Harmonic Balancer does have a slight wobble I will have to repeat the steps of install.

There is a GM number for the tool they specify to start the HB on to the crank.

Frankly given the design and the two step mounting/torquing procedure, I would be shocked if a competent tech got one on less then straight, but there must be a reason somebody at GM thought that tool was important.

Good luck cleaning up these last few glitches.’

 

[Taheezy_88]

It's weird to me cause I followed the steps I thought perfectly maybe it could of got bent during removal idk. I'll buy a entire new one and repeat.

My oil pressure at idle very low. Going to have a shop test the oil pressure for me this week

 

[Taheezy_88]

Harmonic balancer was seated fine guess the lighting really played tricks

Low oil pressure at idle only when car is cold issue.

I was referenced a Melling M355 oil pump so I installed without double checking fitment.

Doing a quick Google search it calls for oil pump part# M295

Could this be the issue?

 

[01FormulaTA]

Harmonic balancer was seated fine guess the lighting really played tricks

Low oil pressure at idle only when car is cold issue.

I was referenced a Melling M355 oil pump so I installed without double checking fitment.

Doing a quick Google search it calls for oil pump part# M295

Could this be the issue?

No...

The M355 is a higher volume pump for engines with AFM/VVT

The M295 is standard volume pump for engines without VVT or AFM

So you would see lower oil pressure with an M295 vs M355

 

[wsteele]

I agree, the higher volume pump shouldn’t be the issue.

Just to ensure I understand the symptom, the oil pressure is low at idle only when the engine is cold? Or low at idle whether cold or warm. Or low when cold and lower when warm?

Did you ever get a chance to test that O-ring with the trucks nose pointed down bill and an overfill.