Help! Failed emissions.....
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Joined: Feb 2003
Posts: 5,524
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From: The South
Help! Failed emissions..... I failed the emissions test today and I have to go back to school next week so I don't have a lot of time to fix it....................printout says
"MIL commaned"
Check engine light status: Commanded ON
Incomplete monitors: EVAP, CATALYST
Diagnostic Trouble Codes: P0155
P0155: 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
I dont know what any of these mean exactly....incomplete monitors? I have 02 sims in there.....I really don't know what's up the engine light has been on and off and it went to the dealer while I was at school a month or so ago and they were suppose to have fixed it but the engine light came back on today (of course) and it has also had troubles with the battery not holding a charge/being drained/or alternator not working that I havn't figured out yet...i Just don't know..........anybody have any comments or ideas?? What exactly does a heater circuit malfunction and the incomplete monitors: EVAP, CATALYST mean?? (I'll take it somewhere when I have time in a day or two to try and fix) THANKS!
"MIL commaned"
Check engine light status: Commanded ON
Incomplete monitors: EVAP, CATALYST
Diagnostic Trouble Codes: P0155
P0155: 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
I dont know what any of these mean exactly....incomplete monitors? I have 02 sims in there.....I really don't know what's up the engine light has been on and off and it went to the dealer while I was at school a month or so ago and they were suppose to have fixed it but the engine light came back on today (of course) and it has also had troubles with the battery not holding a charge/being drained/or alternator not working that I havn't figured out yet...i Just don't know..........anybody have any comments or ideas?? What exactly does a heater circuit malfunction and the incomplete monitors: EVAP, CATALYST mean?? (I'll take it somewhere when I have time in a day or two to try and fix) THANKS!
Joined: Nov 2001
Posts: 34,629
Likes: 2,550
From: Schiller Park, ILL Member: #317
The incomplete moniters are because of the battery power loss/clearing of DTCs after repairs. The PCM runs various DTC tests under certain conditions to check for issues. Once the test completes, you will get a "complete" for that moniter and either a DTC and possibily (likely) a MIL/SES (if there is an issue) or if no problems are detected then no DTCs will be tripped.
The issue for the DTC seems to be with your O2 heater for the front (pre-cat) passenger side O2 sensor. That is a usual code to get for LT header cars because the sensor is moved farther away from the motor, especially in the winter when the temps are colder. You might try a new sensor in that port as a temporary fix to get you past the test. After you clear the DTC though, you'll need to drive the car around for a while and do a couple cold starts to get all the moniters back to "complete" before you retest.
Some cars just seem to take longer to complete all their moniters than others. Mine takes a while for some of them, even when I follow the OBD drive cycle to the letter, it still takes a few times to get them all complete.
Hope that helps.
The issue for the DTC seems to be with your O2 heater for the front (pre-cat) passenger side O2 sensor. That is a usual code to get for LT header cars because the sensor is moved farther away from the motor, especially in the winter when the temps are colder. You might try a new sensor in that port as a temporary fix to get you past the test. After you clear the DTC though, you'll need to drive the car around for a while and do a couple cold starts to get all the moniters back to "complete" before you retest.
Some cars just seem to take longer to complete all their moniters than others. Mine takes a while for some of them, even when I follow the OBD drive cycle to the letter, it still takes a few times to get them all complete.
Hope that helps.
