10+ years of smelly idle fixed by replacing bosch o2 sensors with ac delco o2 sensors
07-25-2017, 12:27 PM
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10+ years of smelly idle fixed by replacing bosch o2 sensors with ac delco o2 sensors
for those of you who arent newbs and have been around here, you know that ive had a lot of success with my car - minus a smelly exhaust on my suprchargd 93 6spd vert
well i finally fixed my exhaust smell issue a month ago when i decided to replace the bosch heated 3 wire o2 sensors i first put in with longtubes.
i went to summitracing equipment and bought ac delco part number 213-1325 heated 4 wire o2 sensors . the 4th wire is a backup ground for the o2 signal sensor vs. the 3 wire which just only grounds thru the (hot) headers. to my delight and amazement, the dusty old boxes summit sent me said made in usa, 1995. i had snagged a pair of new old stock oxygen sensors (vs made in mexico versions that are out today)!!!!
when i got into the job, i found i had installed my heated bosch o2 sensors non-ideally bcause i had soldered an extension wire onto my existing single wire harness for the signal wire.
apparently thats a big no-no. i read a bosch bulletin stating not to solder the signal wire as the o2 sensor breathes thru the strands of wire (which i find hard to believe but thats what they say). So this time i used posi-lock twist crimps to extend the signal wires i also terminated the extension with the proper 4 wire o2 sensor bung connector .
i also attached the 4th wire right to the ecm ground - i wasnt taking any chances.
after a few weeks of driving on it, idle smell is nil. right and left block learns at idle are split a little (normal) but oscillate around 127-131 on left and 136-144 on right. integrators both at 128
this is a major improvement vs where i was at. especially considering i have a cam (224/236) and tons of other mods.
i tune myselfhad tried many times to remove fuel at idle and only have it dump more fuel. with a worse smell.
scanning indicated the car seemed to go into closed loop fine - so i never suspected o2 sensors to be the culprit...i was wrong
well i finally fixed my exhaust smell issue a month ago when i decided to replace the bosch heated 3 wire o2 sensors i first put in with longtubes.
i went to summitracing equipment and bought ac delco part number 213-1325 heated 4 wire o2 sensors . the 4th wire is a backup ground for the o2 signal sensor vs. the 3 wire which just only grounds thru the (hot) headers. to my delight and amazement, the dusty old boxes summit sent me said made in usa, 1995. i had snagged a pair of new old stock oxygen sensors (vs made in mexico versions that are out today)!!!!
when i got into the job, i found i had installed my heated bosch o2 sensors non-ideally bcause i had soldered an extension wire onto my existing single wire harness for the signal wire.
apparently thats a big no-no. i read a bosch bulletin stating not to solder the signal wire as the o2 sensor breathes thru the strands of wire (which i find hard to believe but thats what they say). So this time i used posi-lock twist crimps to extend the signal wires i also terminated the extension with the proper 4 wire o2 sensor bung connector .
i also attached the 4th wire right to the ecm ground - i wasnt taking any chances.
after a few weeks of driving on it, idle smell is nil. right and left block learns at idle are split a little (normal) but oscillate around 127-131 on left and 136-144 on right. integrators both at 128
this is a major improvement vs where i was at. especially considering i have a cam (224/236) and tons of other mods.
i tune myselfhad tried many times to remove fuel at idle and only have it dump more fuel. with a worse smell.
scanning indicated the car seemed to go into closed loop fine - so i never suspected o2 sensors to be the culprit...i was wrong
Last edited by dizwiz24; 07-25-2017 at 12:29 PM.
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whalepirot (07-25-2017)
