I have a 97 Z with a madwolf OBD1 conversion and tune, do I need to hook up the downstream 02 sensor? I have exhaust off now and want to clean up the system if I can.
Thanks

 

Your subject and your question are a little confusing.

With the OBDI conversion, you will still need TWO upstream O2 sensors. However, you can remove or leave plugged in the downstream sensors... doesn't matter because they won't be read but won't screw anything up eihter. So, basically, you go from a required four O2 sensors down to two O2 sensors.

On my 96SS I had the OBDI conversion done as well. I had the resistor soldered in on the OBDI PCM to account for the 100k ohm knock sensor installed in the car to account for the 3.9k ohm knock sensor the OBDI PCM was looking for. I left all four O2 sensors installed and could swap back and forth between OBDI and OBDII in about 5 minutes

 

Thanks Brent, Two questions, why doesn't my E Mail get responses from the LT1 Tech posts but does when I post in the swap section? Have you ever seen someone get a timing cover on and off off a 97 Z without dropping the oil pan? I have 100k on the car and just know it's gonna break the gasket to drop it a few inches? Thanks for this site and everything you do!
Shawn

 

You don't have to drop the oil pan for taking the timing cover off, but you will need to lower it. Pretty much loosen up all bolts. Take the front 6 off completely.

I'd recommend replacing the oil pan gasket anyway while you're doing this since it's pretty easy. Just make sure you clean up the oil pan on the outside and the surroundings real well.
Take all the bolts out, cut the old gasket then you can put a new one in over the oil pan.

With 100K miles, even with the oil pan lowered, chances are you'll break it anyway.

 

Hey Brent I just got an OBD I conversion pcm from Ion in preparation for installing my 383 in my 97 SS. What was that you were saying about having to solder a resistor into the pcm.

Where exactly does the resistor have to be soldered in and what happens if you don't do it?

Please let me know as I'll be installing my motor within the next two weeks, thanks.

 

There is no need to solder or do anything with my OBDI conversion PCM. I already did all of that. Just plug it in and go.

 

Ion, so you are saying I could drop the oil pan enough to change the gasket without lifting the motor up and such? PS I STILL love the OBD1 conversion and tune you did and recommend you every chance I get!!!! Can I just screw in a plug on the downstream 02 sensors and call it a day?

 

Thanks Ion, that's a big relief, I'm glad you make it plug-n-play.

 

Yep, you can plug them. No need to hook them up.
I changed my gasket without lifting the motor. It may look a little intimidating at first (not much room to work with) but it's doable.

BTW, I had new polyurethane motor mounts when I did this so the motor may have been sitting a little higher than on some old 100K motor mounts. So if you can't get enough clearance, you may need to lift it up a bit. (without disconnecting the motor mount)

 

Back when I had mine done (years ago!) if you didn't want to mess with changing the knock sensor you had to solder a resistor in the PCM to account for the 100k OBDII knock sensor. However, it seems as though Ion has taken care of this issue with software. Good deal!