got problem with my lt1 it run not to bad when its cold open loop
but on the highway at 3000rpm it try to go close loop but its start to hesitate and give me right 02 fail code and get back to open loop mode
and i get some little miss on idle
got a datamaster log of it
its lt1 caddy 1996 with pcm from caprice 1995 reflash pcmforless

Sylvain

 

replace your 02.

 

What was the specific code for the O2 sensor? There are more than one, and none of them is "fail".

 

in me my datamaster file it said right 02 fail i change my 02 and test all the wire to the pcm make the of shorting to ground high and low o2 wiring from pcm
and still got 453 on the right 02
on the left it change to 55-400 on ignition on only

Sylvain

 

You got DTC 63 (that's the number I was looking for). When you get the codes, rather than use the shorthand descriptions in DataMaster, use Shoebox's list:

http://shbox.com/1/Dtcs.htm

63 Bank 2 = (right) Heated Oxygen Sensor (HO2S) Circuit (open circuit)

The open circuit could be faulty wires/connector, or the sensor itself. I can't really understand how you tested the wires:
If you could explain that, might be able to help. If you mean you connected the two wires from the PCM together at some point, and you still had 450mV on your scanner, the fault would be closer to the PCM than the point where you connected the wires together. If you hook a high impedance volt meter to the tan and purple wires at the harness connector, what does the meter read?

 

i plug datamaster short the tan and purple wire to ground and it change in th pcm to 9-10
i read that in the service manuel of caddy 94-96
but on the right it stay at 453-458 when i connect it to the pcm with the car not running

Sylvain

 

When the O2 sensor is cold, and the engine is not running, you will see ~450mV on a scanner. The PCM itself supplies that voltage. You have to look at the O2 signal as the engine warms up, and the sensor gets hot enough to generate a voltage of its own.

The tan wire is in effect the "ground". Not sure why you want to short the purple wire to ground. And what does " ...it change in th pcm to 9-10" mean? 9-10 "whats"?

Have you compared the ledt and right sensor signals with the engine cold and not running?

 

it said in the manuel that you are supposed to have like 200mv or less when you short these wire to ground

but when the truck get hot the signal on the left varies but the one on the right stay at 453-458

i compare with the left and got 9-10 when i short the purple and tan wire
to ground

i could send you my datamaster files i you want to take look at ?

 

9-10 WHAT????? Volts, amps, millivolts?????

If you have replaced the sensor, then you have an open circuit between the PCM and the O2 sensor. If you haven't replaced the sensor, swap the left and right sensors, and see if the problem follows the sensor to the left side ( = faulty sensor) or stays on the right side ( = faulty wiring). You don't need someone to look at the DataMaster log. You need to check the things I'm suggesting, and please.... please.... answer the questions I am asking. If you prefer not to answer the questions, and to follow you manual, then tell me and I will back off trying to help, so I don't interfere.

 

so lets forget about the manuel
i switch the 02 and the problem stay on the right side so i check and ohms test my wiring to the pcm and it test ok

so the problem is maybe in the pcm itself