Billiumss

iTrader: (11)

What would cause a LTrim to read -100 all the time, trying to track down a problem. I reset the Fuel trims in HPT and it goes right back to -100 everytime. The O2 doesn't switch either at idle or when you give it gas.

I'm thinking a bad O2 sensor....

What do you guys think, every seen this before?

Bill

ninobrn99

iTrader: (8)

have you switched them around to see if its the sensor thats gone bad or the harness getting burned? maybe the extension if you have one?

Billiumss

iTrader: (11)

haven't tried that yet.

The car in question has/had one of the Dry Kit N20 systems on it that you connect wires to the O2 sensors and it "adjusts" your A/F based on what the O2 are reading. It doesn't work that well.

We unplugged the "brain" and it still reads -100 all the time, but the wires are still connected up at the PCM.

The car had a O2 go out before but for a different problem, but the N20 system was installed at that time as well.

I'm thinking that Dry N20 system is causing more harm than good.

DarkFormula

iTrader: (80)

So this is tapped into the PCM side of the harness, right Bill?

Is this the car with tranny problems as well?

12secSS

iTrader: (30)

I have seen a similar situation, but only one bank was pegged at -100. Turned out to be the wrong PID was being logged. I deleted it and re-inserted the PID and all was good. So the O2 voltage doesn't fluctuate either? It is both banks?

Billiumss

iTrader: (11)

Anthony, yes and nope, different car... (Matt)

It's only bank 2 that stays at -100. The O2 voltage stays to one side, I think the low side.

At the time, I used the standard default scanning PIDs.

I haven't had much time with the car, maybe 10 minutes at our last club meeting.

jimmyblue

iTrader: (11)

I recall LTFTs being clipped at +/-25 and a code being set
if more was needed. I smell bad data.

chrisj6

That is not a sensor error, thats a scanner error. From time to time when i reset mine, they will go to -100, in the scanner setup, they are only supposed to go to +/-25. Did you try starting and stopping the scanner, if so, I would send a log of the problem to HPT support, they have always been really quick fixing issues like that I have had with the scanner.

Chris

SmokingWS6

iTrader: (1)

Agreed its a scanner issue. Last time I had that problem occour I had to many PID's open.