adv5

Hello guys am new to the form and was hoping someone could help me. I currently own a 2001 tahoe with a 5.3l vortec with 184xxx miles which i drive daily. In november 2015 the truck gave me an obd2 code to replace both of my upper oxygen sensors, bank1 sensor 1 and bank 2 sensor 1. After i replaced them i had the codes erased, since then the truck has been giving out the same code in about a 3 week period to replace them again. I just finished replacing the oxygen sensors for the 3rd time in about a 2 month period and have erased the codes every time. I currently dont know what do to at the moment does anyone know what could be causing this?

Thanks.

SlasherVRGR

iTrader: (1)

It's not shooting you lean codes is it? If so look for a leak behind the maf sensor anywhere in the intake tract or manifold. Also I've read that FPR going bad will throw the same lean codes.

My truck was recently throwing lean on both banks due to a giant crack in one of the stock air silencers, so I disconnected the intake and bypassed the silencer.

adv5

Yes I've been getting lean codes on both banks, although the truck runs and idles fine with no smoke.

fbooty

+1 to what SlasherVRGR said.
Check for vacuum leaks, check for correct fuel pressure.

I had lean 0171 and 0174 codes for a year and it turned out I needed new fuel pump and new intake manifold gasket. I suspect the fuel pump swap on a Tahoe is a B**** and a half. O2 sensors are still original, No vacuum leak, and fuel Px correct, original O2's still work just fine. I also had a recently replaced FPR so that took that out of the troubleshoot for me.

If it is the IMG and you do the intake manifold gasket yourself be sure to post a pic of how dirty the top of your motor is, the before and afters are fun. It took me about 6 hours to fully clean mine.

adv5

Now that you guys mention it the truck does hesitate to turn on if it sits for a little longer then 15 mins. So I'll definitely have the fuel pump and fpr checked soon. I'll also check the map sensor while am at it since I was messing around in that area a while back.

Thanks guys appreciate the help

6literc10

Vacuum leak or maf sensor. if both banks are doing it its an issue that distributes to both banks. for example if both banks are saying lean it cant be a fpr leak on one side because itll only affect that one side. im guessing a maf sensor or if it is a vacuum leak its gona be on both sides. run the truck and monitor both banks stft % and spray brake clean around the gasket area and see if the trims change.

SlasherVRGR

iTrader: (1)

You don't want to see mine, dude who owned it before me put a 3in body lift on the truck. It's too easy for stuff to get into the engine bay. If I hit a puddle while turning the bay gets mudded up lol.

As for my codes, they're back. But only on occasion. I'll probably just clear them until the weather breaks and pull the intake and throw new intake gaskets in it, seeing as though it's a pretty common problem.