Original thread for anyone who wants it : https://www.camaroz28.com/forums/sho...d.php?t=592799

I finally hooked my car up to the scanner and ran the car car for about 23 minutes and got some more details:

- code 13, left O2 sensor, and the readings were constantly at 453
- IAC position was at 160 at startup and VERY slowly dropped to around 104 (these numbers are way high of what it should be according to the replies in the OT)
- TPS volts were steady at .71 (dangella stated his tuner strongly recommended about .67)a
Ok so thats what I got, but I did not do any of the adjustments mentioned in the OT yet because I'd like to get my brother to watch the readings for me instead of me running back and forth myself. But I just wanted to let you know and I also have another question... I saw the fuel numbers as well but I'm not sure what they are supposed to be reading. I want to make sure I'm not running too rich or lean while I'm at it. No other codes were thrown so maybe that means it's running fine? I don't know but if anyone could tell me what to look for regarding that I'd appreciate it.

Thanks

 

450 mV is the bias voltage for the O2. This indicates there is an open circuit on either the tan/white or the purple/white wire going to the O2. The DTC13 also indicates this. This is the first problem you should work to remedy. Since this problem is causing you to run in open loop all the time.

If you require a lower TPS voltage at idle, you will probably require slotting the TPS to allow it to rotate more with the aftermarket TB.

IAC position would most likely be the result of trying to keep a poor running engine going. After getting it into closed loop, see what the IAC numbers are.

 

Funny you should bring this thread back up. I just started it up again today for the first time since I originally posted. I don't really have anything else to do, so I think I will see what I can do with it today. Only problem is, I have two new O2 sensors, but no extensions yet

 

BTW what do you mean by "open circuit", is it something I might be able to fix right now, without replacing the whole sensor yet?

Thanks

 

Open circuit = broken/disconnected wire somewhere.

 

I just went out and looked and couldn't see anything broken, so it must just be bad wire somewhere or something. I'm ordering 24" extensions right now and I'll replace everything all at once then. I'm also trying to get it in to have the header leak fixed and then dyno tuned, might be a little while though.

 

Quick question, what type of extension do I need? I know I need the 24" but is it the flat or square 4 pin?

 

Rear o2s are square. Front o2s are flat.

 

I think I'm working with the front O2's, they're the ones attached to the rear of the headers.

 

Well in 95 you had dual cats and the front o2s were flat. Do not buy square extensions. Square extensions are for b-body cars. F-bodies use flat o2s for the front.

 

It wasn't until 96 that they added after cat O2s along with OBDII to monitor cat efficiency only.

Adding extensions will not fix your problem. You have a break in the wiring somewhere between the PCM and the O2.

You need to remove the white connector from the PCM and jump pin 19(tan/white wire) to pin 20(purple/white wire) together. Now with the O2 disconnected, measure the resistance of those 2 wires at the O2 connector. The reading should be close to 0 ohms. But because of your break in one of those wires, it will read very high if not infinite. Now start wiggling wires until you see a change in the reading.

Focus your attention on any where the bundle nears heat or a corner.

 

I am going to bet that the IAC bypass is not drilled on your TB and the blades are cracked slightly to get the idle. No need to slot the tps if you correct the real issue of lacking the IAC bypass. Smooths the idle by using the distribution circuit GM went through the trouble of machining into the manifold too.

 

So it seems like my problems are going to be a little more difficult to fix then I originally thought. Well I'm kind of debating now doing it myself or letting the dyno shop do their thing with it. They do have a lot of experience with LT1's and have built quite a few fast ones on the dragstrip. And I don't have as much time on my hands as I did when I did the whole swap... I'll have to talk to them and get a price and all that, before I make a decision. On the plus side, hopefully they will take care of all the issues and then it will be dyno tuned all in one punch, I won't have to break things up into little pieces myself.

 

Look down the shock tower on the passenger side of the car. There is the main wiring harness for the PCM and the connector for the ABS is attached there also. Make sure those wires aren't brittle or broken. Are you picking up knock retard?

 

I don't know if I'm getting knock retard and I'm not sure how to check for that. Remember, it has a leak at the header gasket on passenger side, if that would have anything to contribute to knock, then I could very well be getting it.