o2 sensor disconnected - no ck eng light?
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
o2 sensor disconnected - no ck eng light?
Went to install 2 fresh o2 sensors on my 94 LT1 to find the passenger side sensor not even plugged into the harness! Never once tripped a check engine light! Is OBD I that oblivious?
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
Was the disconnected sensor before or after the CAT? I seem to recall 94's having a post cat sensor. My understanding is that GM collected and used the data to prepare for catalyst monitoring which began in 96 with OBDII. The 94 and 95 post CAT sensors will NOT turn on the MIL, but you may be able to retrieve a code with a scan tool.
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
Per-cat sensor. Which is why it shocked me that it didn't trip a code. Believe these were the original sensors as well - but no sure way to tell. They were frozen in the pipes pretty good, rusted a bit and stamped AC. Carbon stained but no chunky buildup.
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
I couldn't tell. Seemed to run fine. I usually get around 15mpg but I chocked that up to being a weekend car, driven mostly in town and I like I work the lt1 out every so often. I can say with the new o2 sensors I haven't noticed a difference but I only drove for about 5 mins just to make sure all was well after replacment.
