I have done some things to fix scan codes on my 97 45.2 Dak.

After the repair (which i apparently botched, see below), the MIL did not return. (check engine light stayed out). But the two previous codes were stored. (P0107 and P0138---one being low voltage to MAP and the other being a faulty signal from/to an O2 sensor--I had replaced the #1 O2 sensor ...P1038, IIRC, refers to a downstream unit issue. and checked map voltage, which was fine.

I interpreted these codes to be caused by a botched job on my part of installing a generic cut-in O2 sensor on an earlier round of trouble shooting (multiple splices in the leads).

So I replaced the botched #1 sensor with a complete stock type Bosch sensor and simply plugged it in.

After that the MIL went out right away but the stored codes would not release until I cleared them with a borrowed Actron 9125 scanner (slick tool, about $100 on Amazon) 200 miles later.

Then, another 120 miles later "not ready" was still displayed, Can't get it past smog with either stored codes or not ready. This is California.

So it was back to the Actron 9125 and the testing looked ok for everything but it had not completed the testing required for the O2 Sensor Heater Monitor what was listed as incomplete.

After 120 miles including several open loop (floored the sucker for 30-60 seconds) as well as two "cold" starts (ambient about 70 degrees) there should have been enough opportunity to either pass or fail (i.e. to fail 3x thus setting a code).

Could this be simply a poor connection...somewhere? Where the htd cicuit works not it doesn't. Or does it suggest I need to drop more $ on it and gofer a #2 sensor.

I'm going to pursue the connection issue in my next under the (&(*&%^ session.

But comments from those which more knowledge abotu this than I would really be appreciated.

 

check blue 15amp fuse in your PDC for 02sensors. I had p0138 and that fixed mine. good luck.