jinxed45 Posted January 20, 2006 Report Share Posted January 20, 2006 Well, technically I passed my smog test according to the numbers but my "MIL" failed (Service Engine Soon light). Pulled the codes, P0146 seems to be the only one affecting emissions. O2 Sensor Bank 1 Sensor 3, simple.. replace it right? Well.. I have had this light for a while, I even changed the Bank 1 Sensor 3 with an ACDelco O2 sensor, brand new at PepBoys. The light never went off, the PepBoys guy said "We changed it, it'll cost more for us to look into it." The mechanic that did the smog test was really cool.. he diagnosed a little bit.. found that the harness that supplies power to the O2 is receiving 12 volts of power (which is correct). SO... if it's not the O2 Sensor itself, or the wires.. what is it?! Computer? 1997 Cadillac Eldorado ETC 130k Link to comment Share on other sites More sharing options...
Ranger Posted January 20, 2006 Report Share Posted January 20, 2006 How long ago was the sensor changed? If the code was not cleared, it will take 3 ignition cycles with no fault detected for the light to extinguish and go into history. Link to comment Share on other sites More sharing options...
Spurlee Posted January 20, 2006 Report Share Posted January 20, 2006 Clear the codes and the MIL light will likely go out. One other thing - Bosch makes a universal and a direct-fit O2 sensor. The direct-fit has the correct length and style of connector to fit the application (Bank1, Bank2, etc.) The Universal fit is the same sending unit, but with no electrical connector but, rather, a splice kit. The splice kit is pretty nice - I've used several with no ill effect - and the unit is a lot cheaper because if it's wider application. If you're still experiencing problems after clearing the codes it could be that if they used the Universal fit unit, the wires in the 4-wire splice aren't properly seated. It can be tricky to get them properly set in their little housings. I'm surprised Pep Boys didn't clear the codes when they released the car... Scott 1996 El Dorado 2006 STS 2000 Corvette Link to comment Share on other sites More sharing options...
jinxed45 Posted January 21, 2006 Author Report Share Posted January 21, 2006 I manually cleared the codes using the "Off Up" Method, and also disconnected the battery. Anyways.. The Smog Test guy that tested for 12 V reset the codes yesterday.. and after 16.7 miles of driving, the light popped back up P0146. The O2 Sensor used at PepBoys was an ACDelco O2 Sensor made specifically for my car! I'll probably try switching a new O2 sensor.. but does ANYONE know what else could be wrong? Also.. thanks for the replies. Link to comment Share on other sites More sharing options...
KevinW Posted January 21, 2006 Report Share Posted January 21, 2006 If 12 V was measured at the sensor connector, all that confirms is the heater circuit is receiving B+. I'm guessing that sensor 3 is located after the exit of the catalyst, and is intended to assist in the monitoring of catalyst efficiency. The simplest way to investigate would be to connect a scan tool and monitor O2 sensor voltage for B1S3. Given that a DTC P0146 was been triggered, chances are there'll be little activity on this input. To check the wiring from the PCM to sensor connector, see if the 0.45 V reference is available at the connector. If all the wiring is intact (up to the PCM connector), and the sensor (warm) has some voltage output, it is possible there's a hardware fault in the PCM. ___________________________________________________ Link to comment Share on other sites More sharing options...
jinxed45 Posted January 22, 2006 Author Report Share Posted January 22, 2006 The Bank 1 Sensor 3 is before the cat.. first two are manifold, third before cat, fourth after cat. Anyways, I'm going to change out the O2 sensor again.. see what happens from there. I'll keep this updated. Anyone else with any ideas would be great! Link to comment Share on other sites More sharing options...
JimD Posted January 22, 2006 Report Share Posted January 22, 2006 The Bank 1 Sensor 3 is before the cat.. first two are manifold, third before cat, fourth after cat. Anyways, I'm going to change out the O2 sensor again.. see what happens from there. I'll keep this updated. Anyone else with any ideas would be great! I believe the sensors are identified as: Bank 1 Sensor 1=Exhaust manifold for cylinders 1-3-5-7 B1S2=Pre-cat B1S3=After-cat B2S1=Exhaust manifold for cylinders 2-4-6-8 And B1S2 was not installed after some point during the 1998 production model year (as information for those with '98 and later models). Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
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