Autotap Scanner on 4.0 OHV

[steve6534]

Has anyone used this device against an OHV 4.0 ? I scanned my '96 yesterday and saw a few strange things :

1. All o2 sensors showed next to no output at engine speeds below 1200 rpms
2. The starting % of the TPS sensor shows 20%.

I'm going to measure the TPS voltage manually to get a reference but the o2 readings seem pretty strange to me.

 

[wpurple]

I have used my Autotap on my 97 OHV 4L and had no issues. Running software ver 2.05 It is one of the first versions they made.

It works for my 97 4L 99 5L and 06 5.4L with no problems.

 

[steve6534]

I have used my Autotap on my 97 OHV 4L and had no issues. Running software ver 2.05 It is one of the first versions they made.

It works for my 97 4L 99 5L and 06 5.4L with no problems.

Do your o2 sensors provide output at idle ? Mine work fine with a little load on the engine but are almost flat at idle causing the short term fuel trim to max out to correct the "lean" condition.

 

[viper1314]

I don't know the name of the scanner, but we hooked mine up the other day to check the coolant temp and the scanner showed all my O2 sensors at -100% and 0 voltage. But no error codes relating to the O2's. Only error code was the p1405 and I replaced the hose for that , as it was busted in half.

mine is the 98 v6 ohv


Edit: I was reading about this on google, and the reason for the 0 voltages could of been the thermostat that was stuck open. be interesting to put it back on the scanner now that I put a new thermostat in.