Fuel system is to lean

[PKRWUD]

Originally posted by grant66
So I first disconnected the negative post to the battery for eleven minuites and turned on the head light switch to reset the codes. (I don't believe this matters because we didn't have any hard codes in the computer) I took the hypertech chip out of the car. Ran the car for 4 minuites at 2000 RPMS. I then shut the car down for 10 seconds. The next thing I did was started the KOER test with the OTC scanner. The scanner ran me throught KOER test and came up with the 21, 41 and 91.

All I asked you to do was run it at 2000 rpms for 4 minutes, and rerun KOER.

Your problem is in one of 3 areas. You either have a fuel pressure problem, a vacuum leak, or a problem with the O2 sensors and/or their wiring. There is only one more test that you will be able to do as far as your sensors are concerned, and that is to check them to see if they can generate the necessary voltage. To determine this, you need to disconnect an O2 sensor, and attach a DMM pos lead to the signal wire from the sensor (either the dark blue/light green wire, or the dark green/pink wire), and the DMM neg lead to the neg battery post. Then run KOER, and monitor the DMM. If the voltage is over .5 vdc, then the sensor is good. If the voltage stays below .5 vdc, then the sensor needs to be replaced. After testing one, test the other.

Did you already check your fuel pressure?