zTimbo

My swap constantly and consistently throws P0154 both banks no activity and P0327 for both knock sensors after about 20 minutes of run time. This is a brand new build with 150 miles on it with all new sensors and a new PSI stand alone harness. At first I was told it was probably tune related and I should have it tuned. I called the only tuner that is close to me and I've dealt with them before. I knew to prepare myself for this guys arrogant attitude from past experiences, he's good at what he does and he doesn't mind letting you know either. Anyways, from the way he talked it seemed like he really didn't even want to mess with it after he quoted me $100 per hour and roughly 20 hours to figure out why it's throwing codes. He also stated that because they didn't build the harness the PSI harness was probably built wrong.

Personally I feel like this is going to end up being something like a ground. I just don't know how it could be when I've got all the grounds done like the PSI manual states.

Any ideas???

zTimbo

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58Rag

What engine is in it? What are you using to pull codes and does it have data display?

zTimbo

It's a rebuilt 5.3 bored .040 with flat top Pistons, stock cam and a ls1 intake.

Used a small handheld OBD II scanner to read codes. It has live data and showed my 02 sensors are getting voltage but they're not sending anything back.

58Rag

And what is it showing for the knock sensors? I would probably physically check for voltage and ground at the o2's. I'd hate for the scanner your using to give you false readings. I use a Solus Ultra daily at work, and all it gives me is a mv reading from the o2's. It doesn't say that its sending a certain amount to the sensor. SO...The data shows what at the o2's? Just 0mv?

zTimbo

I physically checked for voltage at the 02 sensor connector. I have 4 wires.

12v
Ground
5v
5v

Does that make sense??

I haven't checked at the knock sensor yet.

zTimbo

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zTimbo

I've checked everything I know how to check and haven't found any issues. My 02 sensors appear to not be communicating and I have a bunch of goose eggs next to my stft and ltft.

zTimbo

I replaced both 02 sensors with Bosch units and I now have fuel trim data!

zTimbo

02 sensors are working properly.

After some checking I'm still not getting proper voltage to my knock sensors. I checked at the pig tail and coming out of the PCM and im only reading .5 volts. These are pins 51 & 11 on the blue connector. PCM is from a 2000 Chevy truck. PCM was sent to PSI when I ordered my harness for whatever they do to it. Should I suspect a bad PCM?

zTimbo

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58Rag

Good to hear the new o2's got the issue solved on the 154. As for the knock sensors, have you replaced the harness from the sensors to the main harness? Voltage key on engine off should be 5v. Is the .5v at the computer...or the end of the harness at the sensors?

zTimbo

As you stated, I suspected the harness for the knock sensors.

I checked it there, at the pig tail connection, and at the PCM and I'm only getting .5 volts. Which makes me think PCM issue.

zTimbo

Anyone?

58Rag

IMO if both 11 and 51 have .5 volts KOEO, I would suspect a PCM.

zTimbo

Finally got in touch with PSI and after speaking with them they suggested I send the PCM to them since they suspect there are some problems......