68 C10 with 5.3 help

[smallblock500]

my buddy and I have been working on his C10 that he put the 5.3 in. The ECM says 03 yukon and the harness is a stripped down OEM harness. last night was the first night at the track with it and for some reason the o2s don't seem to be reading right and its not showing fuel trims?

ill include the current .bin. its pretty stock other than the removal of the codes for the stuff that is no longer on the truck and the TM. also a short log from one pass at the track.

[flame]

Are there even O2 sensors hooked up? They never move off the reference voltage which usually indicates they are unplugged. All the O2 codes are turned off so you would not know if you had a problem. Why are the MAF codes turned off when you are running a MAF?

[smallblock500]

That was from when their was no MAF or o2s. When the motor first went in he removed all of that from the harness with plans on just running SD. We could not get it running on SD so I had him put that stuff back in the harness for now. He does have the o2s and MAF on the truck and I just varfied that that they were in fact plugged in during those logs and wired right.

I totally forgot to turn the codes back on after that stuff was put back in the truck but I will turn them back on and get some more logs.

thanks for your help so far

[acehaag]

check your grounds. I missed a wire when I did my harness the first time and had the same problem. I needed to add a ground to pin 63 in the blue connector and tie it to the tan wires at 26 and 29 in the blue connector.

[EagleMark]

There's also 2 differant O2 sensors, one case ground and one isolated ground. The sensor has to match the harness wiring.

[smallblock500]

ya I know he said something about the o2s that he needed were only used on the trucks for 1 year and they have a different plug than the rest so he had to buy o2s for whatever year truck the harness came from.

I have turned the bank1 sensor1 and bank2 sensor1 o2 codes back on as well as the MAF codes so when I get back out to burn the new file on the truck and another log I will report back.

thanks again guys for your help.

[smallblock500]

still no LTFT or STFT or even readings from the o2's. he says they are wired right but thinking maybe the sensors are shorted out inside? he said he bought them from a wrecked cady so maybe they got jared in the wreck and are both bad somehow?

anywho here are the logs from this weekend at the track. only got to log one pass before the laptop died.

[Dantheman167]

still no LTFT or STFT or even readings from the o2's. he says they are wired right but thinking maybe the sensors are shorted out inside? he said he bought them from a wrecked cady so maybe they got jared in the wreck and are both bad somehow?

anywho here are the logs from this weekend at the track. only got to log one pass before the laptop died.

generally if not always when you have a bad 02 in the upstream position, your vehicle will run like shit all the time. the upstream o2 sensors are what the computer uses to basically "tune" your vehicle. that is if your computer is set up to take its reading from the o2 like a stock vehicle does. try probing your 02 sensor wires while your vehicle is running and the o2s are plugged in. also if you replace the o2s and plan on having the computer use them then dont get that stupid bosch smart link crap. go with oem sensors, they last the longest.