Poo53 Code Help!

[MOFAT]

I purchased a 2005 Chevy Express Van 2 months ago and of course it ran great on the test drive and 2 days after I purchased it a "check engine" light came on. My first engine scan, it gave me the following codes: Bank One Lean, Bank One Missfire, Bank One Sensor One and Heater. Dealership told me that it was the intake manifold gasket. Took it home to investigate the intake manifold gasket and found out that it wasn't sucking in any air. I got a second opinion and the second shop told me to replace the O2 sensor, so I figured I would do that first, since it was cheaper. Replaced the O2 sensor and cleared the code and 2 days later the "check engine" light came on and the code showing was POO53. So, I investigated things further and found 2 bare wires rubbing on the doghouse. Repaired the wires, reset the PCM again, 2 days later, "check engine" light again same code!!!! Replaced 02 sensor again and reset code, 2 days later code again. I am pulling my hair out, does anyone have ANY suggestions????? Your help is appreciated, thanks in advance.

 

P.S. O2 fuse sensor is ok

[bill190]

Let's see...

 

Lean implies not enough fuel. Is the side with the lean condition the "end of the line" of the fuel system? (Like pass the food down the table and not enough left for the last person?)

 

So for this theory, I would check fuel pressure and volume. Here is info on that...

http://www.asashop.org/autoinc/june98/techtotech.htm

 

For checking for a vacuum leak, the following page has a good test using propane...

http://www.random-misfire.com

 

As for the heated oxygen sensor, this gets power to heat it up. I suppose you could check the fuse/power for this. And if an intermittent problem is suspected, you could monitor the voltage on the heater portion of the wires to this by tapping into the wires, running a couple of wires into your vehicle, and monitoring the voltage with a multimeter.

 

More...

http://members.shaw.ca/betterthanyoutoo/ho...ygen_sensor.htm

 

How to use a multimeter...

http://www.google.com/search?hl=en&saf...ter&aqi=g10