CEL came on yesterday, 2006 ODB trouble codes

[2006Tahoe2WD]

So, basically, as long as you make that fat/wide spot disappear, it is aligned correctly, but don't over do it and go too far.

Yes, you don't want to get to the point of "bottoming out" the switch in either direction.

 

[2006Tahoe2WD]

Near the end of this video Eric O shows the purge and seal test, and how to understand the fuel tank pressure and vacuum decay.

MORE: Mike at Wells does a great job of explaining and testing:

Very good instructions on running the purge/seal test. I'm going to redo that and see what happens and report. Working on the car today is limited - we are having a big rain storm. Please stand by.

 

[D -money]

Genuine GM, AC Delco or Delphi sensors. I would do all 4 at same time. Typically not hard but if live where salt on roads, your rust may impede your success. Lots of penetrant will be needed.

Why do you think the codes accumulated over a long period of time? have you had CEL on and just ignored? Right now, you are guessing and that is exactly what the codes are for, to keep from guessing. Unless of course you have been ignoring the CEL.

By the way, when it comes to repairs and maintenance, lazy costs money. See my signature.

Hi i was wondering if you have a code reader and if so the brand

 

[2006Tahoe2WD]

My scanner is a Foxwell NT510 Elite Multi-System Scanner.
Today I ran the evap/purge test. It builds vacuum pretty easily but quickly goes down when I push "seal". Also, I went into manual mode and turned the vent valve on and off and I could hear it clicking. It wasn't a very loud click. That's where I'm at.

 

[truckguy]

NY wife's 4 runner kept coming up with cel and evap codes.
I took the gas cap off, and flipped the rubber o ring inside the gas cap inside out and also cleaned the lip on the gas tank fill tube. Been 4 months and no more codes. Might try it.

 

[OR VietVet]

Hi i was wondering if you have a code reader and if so the brand

I have an ANCEL AD530 for quick code reads and such.

I have a Foxwell NT630 Plus for in depth searches.

 

[D -money]

I have an ANCEL AD530 for quick code reads and such.

I have a Foxwell NT630 Plus for in depth searches.

Thank you sir and can you make it warm again for us.? Brrr ..hands frozen workin on the **

 

[OR VietVet]

Thank you sir and can you make it warm again for us.? Brrr ..hands frozen workin on the **

I moved to Eugene, Oregon in 1996, to get away from extreme temps of KC, Mo. area. I recently almost moved back after retirement but then I remembered why I moved here. We recently had a 100 year ice storm and was as bad as I have seen here. Most snow I have seen is 6". Can go to mountains to get whatever. I am on the Valley floor here and it mainly is just rain. I can deal with that.

 

[2006Tahoe2WD]

Ideas on next steps?
I'm thinking when it clears up I'll get it in the air and look around.
So far:
1 - fuel tank pressure sensor reads 1.3 ish volts and goes up and down during the evap/purge test. So I think it is good.
2 - purge valve is working and doesn't appear to leak but I'm not sure. Could be leaking a small amount when closed?
3- I hear the vent valve clicking.
4 - When I hit the seal button on the scanner the pressure goes to zero in less than 10 seconds.

 

[Fless]

Test that vent valve by applying 12v to it and try to blow through it -- best done on a bench, probably. Just because the solenoid works doesn't mean the valve is fully sealing.

After disconnecting the hose you can try to blow through it while toggling it on/off with the scanner, or remove it from the truck and apply 12v (polarity doesn't matter for this test) alternately to see if it seals every time. With no voltage applied it should be open, and with 12v applied it should seal. Every time.