89 Chevy c1500 Oxygen Sensor Problems??

[Sgt. Genocide]

I think I may have posted the following plea for help in the wrong section ( Chevrolet - General Discussion ) instead of posting it here. If ANYONE can help solve my issue please let me know.. I am lost.. Thanks in Advance.. Ok guys here is my Dilemma, I have a 1989 Chevy C1500 w/ 350, T.B.I, Automatic Trans, Mileage = High, that keeps throwing the Trouble Code 13.. I can crank the truck and drive it and it runs great BUT as soon as the engine gets warm(5 -10 miles) the Check Engine Light comes on and I can tell a noticeable difference in power (loss).. I have to press a little more on the gas pedal to maintain my current speed.. As you know a Code 13 indicates a faulty O2 Sensor, I replaced it with NO LUCK.. Could I have bought a faulty O2 Sensor? I have heard of Brand New P.O.S Before.. The old O2 sensor was white on the end if that helps any and I checked the voltage of the wire coming from the ecm with the switch in the on (not running) position and I got a voltage of 1.5volts if that helps any.. Oh and all this started all of a sudden after I done a complete tune-up on the engine. New Plugs,Wires,Cap,Button,PCV,Air Filter,Oil and Filter, New Thermostat and Gasket.. Any help would be GREATLY APPRECIATED and I am willing to try anything at this point even if it may sound odd... Thanks for any Help.

[rhandwor]

Your converter can be4 checked with a heat gun.
http://www.rockauto.com/ Look at video on checking converter.
google u-tube videos for catalytic converter checking.
http://www.ebay.com/ Look at item 111393747078
Ask for rental at parts store.

[j cAT]

disconnect the O2 sensor see if it fails exactly the same if so then the circuit is open. make sure the wire is not shorting out or pin damaged.

could be a bad O2 . when the engine is running you should get .5 volts approx.

[rhandwor]

Vacuum and exhaust leaks will also cause the problem.

[Schurkey]

I chased a false "lean" code--maybe 43--at highway speed. As the defect progressed, the code would set at lower speeds. Started at about 65 mph, by the end it would set at 45 mph.

I checked "everything" that would put excess O2 in the exhaust stream--vacuum leaks, faulty AIR diverter valve operation, faulty fuel pressure. Replaced the throttle body thinking I might have partially-plugged injectors. The complete "tune up" thinking I might have mild misfire. O2 sensor operation at low exhaust velocity was fine--reasonable crosscounts, reasonable voltage range. After dicking with it on-and-off for two years, I finally just replaced the O2 sensor. Problem gone.

Tell me this:

1. Have you followed the GM diagnostic chart for your vehicle for Code 13? and
2. Have you put a REAL scan tool on the vehicle to inspect the data stream?

[Sgt. Genocide]

I have not placed it on a Scanner yet, I have been just using the old jumper wire trick. At current I do not have access to a ALDL Scanner.. As for following GM's Troubleshooter for code 13, I don't know where to get it. Granted, I may have tried SOME of the things GM suggests but as far as Step By Step, Negative.. My truck has had the Converters chopped off and Dual Glass Packs ran out the back ( Previous Owner).I have been doing some more research and have found out the O2 sensor is in Open Loop ( Already Knew ) when first started until the engine reaches normal operating temperature, thats when my CES light comes on and I start having the power loss.. But I found out that if at anytime while driving, I place the engine in a WOT ( TPS = 80% or more) state for 2 or more seconds, the ECM will Open the Loop to the O2 sensor.. Sure enough I tried it this morning and the CES went out. It stayed out for a few minutes and came back on with the Power Loss.. Just based on this new info, I am really wondering now If I bought a defective O2 sensor.. Any Suggestions? Thanks again guys, ya'll don't know how much it means to me that someone is actually helping me with this. I really appreciate it..