Im in the process of swapping headers on my car and noticed while taking them out that there is only one o2 harness on each side. I don't see a second set for after the cats... in fact there isn't even provisions for them (he installed catback exhaust). Which leads me to believe the car was converted to ODBI. Is there a simple way to definitively determine this? PCM part number? Visual differences?

Camaro is a '96

 

OBD1 does not use a crank position sensor but I doubt that the harness or sensor were removed.
Your best bet is the PCM part number.

 

I agree. It seems like too much work just to convert to ODBI but I cant seem to find the secondary o2 harness wires hiding anywhere.

 

Look at the tail s. there should be one of your after cat o2 senser plugs there my sons 96 ta has a odb1 in it we run 94 rk sports headers on it which have only 2 o2 `s The other plug is on the harness that has your right side front o2 .

 

You can switch to OBDI pretty easily. Change out the knock sensor and PCM. Only real way to see if you're OBDI is cross-referencing the part number on the PCM. If changed, you'll still need the OBDII diagnostic port cable for any tuning/datalogging.

 

You don't have to change the knock sensor, just solder in a resistor and its plug and play. Some claim success with just turning off the code that pops up from having the wrong sensor and still having full functionality.

The cable you need after conversion has an obd2 connector but is not wired like obd2 at the pins.

 

True. Changing the KS is no big deal (dealing with the coolant is the biggest PITA), but soldering in a resistor does work too.

Thanks for clearing up the cable issue too.

 

I would look up by the trans.....I'd bet that it's still obd II with the rear o2's deleted for emissions compliance, that way you don't get a check engine light (and in IL's case an instant failure on your emissions). That's my first instinct...

 

So do the before cat o2 sensors very between odb1 and odb 2? Say '94 and '96. Reason I ask is cause the headers im installing came off my '94 and im wondering if can reuse the o2 sensors as they're relatively new. Or does this depend on if the car was switched to odb1. I wont be able to cross referance the PCM part number till tomorrow.

 

Makes no difference at all. If the o2's will hook up to the harness they will work just fine. I am fuzzy on the o2 sensor connector but I think all of the front o2 connectors are the same.

 

Cool. Thanks!

 

my o2's on my 93 are 1 wire sensors. I'm pretty sure the obd2 stuff is 4 wire, so I would think they're different.....just my $.02

 

Your 93 doesn't have jack crap to do with 94 and 95 obd1 cars either. I am sorry but obd 1 MAF cars do exist and have nothing to do with the stone age pcm that came in the 93 models.

 

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Thanks, I know about the obd I maf cars. I also know that obd I has one o2 sensor on either side pre cat. Now the obd 2 cars have two on each side, one to monitor a/f and another to monitor the cat efficiency. Now as for the pcm in the 93's......it's neither here or there but I like it, reminds me of my 90 and a buddies 92 that we ran. Both computers are easy to tune, as long as you have the chipset and the burner. Plus its a hell of a lot cheaper to buy that stuff than.....insert LT1 tuning software name here......

All my original comment said was to look for the rear o2 sensor connections. I'm betting he will either find sims there or open connectors which would lead me to believe that they were deleted from the program. If they are just not connected then he can look into the pcm part number and determine if the previous owner swapped the pcm. I'm sorry I had to spell it out for you, I thought everyone here could gather that....I apologize for assuming....