For the last 3 months or so my car has had an SES light on indicating that all 4 O2 sensors are bad and it has been running a bit rich and has gone into limp mode a couple times over the last week. Two additional codes came up after going into limp mode, one for the Throttle body sensor and one for the ECU.

Since this all of the 02 sensor codes happened at one time I suspected that this TSB might apply. After having the dealership reflash the ECU the SES light came back immediately with the same 4 codes, P1148, P1168, P1051, and P1031. The dealership pretty much refused to troubleshoot it any more as there are aftermarket parts on the car. I now suspect that perhaps the ECU is bad but don't know for sure.

When observing the values for the O2 sensors they all seem to read .6 and doesn't budge and the system stays in open loop. Interestingly the TSB pdf document indicates that values should be between 1.37 and 1.57 volts. I was under the impression that o2 sensors maxed out at 1volt...

So I am trying to determine whether it is perhaps the case where I would need to replace the Throttle Body/Sensor and all four O2's or crack open the ECU and look for damage. I should mention that the seal that the ECU wiring harness goes through in the firewall has leaked in the past and gotten the ECU wet along with the UTEC piggy back that I was using at the time.


Any thoughts/suggestions are appreciated.